diff --git a/individual-shell-tools/awk/script-01.sh b/individual-shell-tools/awk/script-01.sh
index 8db4390a..336b3fd5 100755
--- a/individual-shell-tools/awk/script-01.sh
+++ b/individual-shell-tools/awk/script-01.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output just the names of each player in `scores-table.txt`.
 # Your output should contain 6 lines, each with just one word on it.
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/awk/scores-table.txt"
+awk '{print $1}' $path
\ No newline at end of file
diff --git a/individual-shell-tools/awk/script-02.sh b/individual-shell-tools/awk/script-02.sh
index 5956be9b..828fabb0 100755
--- a/individual-shell-tools/awk/script-02.sh
+++ b/individual-shell-tools/awk/script-02.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the names of each player, as well as their city.
 # Your output should contain 6 lines, each with two words on it, separated by a space.
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/awk/scores-table.txt"
+awk '{print $1, $2}' $path
\ No newline at end of file
diff --git a/individual-shell-tools/awk/script-03.sh b/individual-shell-tools/awk/script-03.sh
index af7c6e8b..f8561ed5 100755
--- a/individual-shell-tools/awk/script-03.sh
+++ b/individual-shell-tools/awk/script-03.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # TODO: Write a command to output just the names of each player along with the score from their first attempt.
 # Your output should contain 6 lines, each with one word and one number on it.
 # The first line should be "Ahmed 1".
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/awk/scores-table.txt"
+awk '{print $1, $3}' $path
\ No newline at end of file
diff --git a/individual-shell-tools/awk/script-04.sh b/individual-shell-tools/awk/script-04.sh
index bf15703c..15ca5e93 100755
--- a/individual-shell-tools/awk/script-04.sh
+++ b/individual-shell-tools/awk/script-04.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # TODO: Write a command to output just the names of each player in London along with the score from their last attempt.
 # Your output should contain 3 lines, each with one word and one number on it.
 # The first line should be "Ahmed 4".
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/awk/scores-table.txt"
+awk '/London/ {print $1, $NF}' $path
\ No newline at end of file
diff --git a/individual-shell-tools/awk/script-05.sh b/individual-shell-tools/awk/script-05.sh
index d1680cb0..29aa79ae 100755
--- a/individual-shell-tools/awk/script-05.sh
+++ b/individual-shell-tools/awk/script-05.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # TODO: Write a command to output just the names of each player along with the number of times they've played the game.
 # Your output should contain 6 lines, each with one word and one number on it.
 # The first line should be "Ahmed 3".
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/awk/scores-table.txt"
+awk '{print $1, NF-2}' $path
\ No newline at end of file
diff --git a/individual-shell-tools/awk/script-06-stretch.sh b/individual-shell-tools/awk/script-06-stretch.sh
index 0201e637..bf9e60a4 100755
--- a/individual-shell-tools/awk/script-06-stretch.sh
+++ b/individual-shell-tools/awk/script-06-stretch.sh
@@ -6,3 +6,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the total of adding together all players' first scores.
 # Your output should be exactly the number 54.
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/awk/scores-table.txt"
+awk '{sum += $3} END {print sum}' $path
\ No newline at end of file
diff --git a/individual-shell-tools/awk/script-07-stretch.sh b/individual-shell-tools/awk/script-07-stretch.sh
index 3f715588..38eb8bed 100755
--- a/individual-shell-tools/awk/script-07-stretch.sh
+++ b/individual-shell-tools/awk/script-07-stretch.sh
@@ -7,3 +7,9 @@ set -euo pipefail
 # TODO: Write a command to output just the names of each player along with the total of adding all of that player's scores.
 # Your output should contain 6 lines, each with one word and one number on it.
 # The first line should be "Ahmed 15". The second line should be "Basia 37"
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/awk/scores-table.txt"
+awk '{
+  sum = 0
+  for (i = 3; i <= NF; i++) sum += $i} {
+  print $1, sum
+}' $path
\ No newline at end of file
diff --git a/individual-shell-tools/cat/script-01.sh b/individual-shell-tools/cat/script-01.sh
index c85053e0..7d0f34ba 100755
--- a/individual-shell-tools/cat/script-01.sh
+++ b/individual-shell-tools/cat/script-01.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the contents of the helper-1.txt file inside the helper-files directory to the terminal.
 # The output of this command should be "Once upon a time...".
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/helper-files/helper-1.txt"
+cat "$path"
\ No newline at end of file
diff --git a/individual-shell-tools/cat/script-02.sh b/individual-shell-tools/cat/script-02.sh
index 01bbd5ea..2cff2c63 100755
--- a/individual-shell-tools/cat/script-02.sh
+++ b/individual-shell-tools/cat/script-02.sh
@@ -11,3 +11,5 @@ set -euo pipefail
 # It looked delicious.
 # I was tempted to take a bite of it.
 # But this seemed like a bad idea...
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/helper-files"
+cat "$path"/*.txt
\ No newline at end of file
diff --git a/individual-shell-tools/cat/script-03.sh b/individual-shell-tools/cat/script-03.sh
index 37573b0c..c14b1037 100755
--- a/individual-shell-tools/cat/script-03.sh
+++ b/individual-shell-tools/cat/script-03.sh
@@ -9,3 +9,5 @@ set -euo pipefail
 # 1 It looked delicious.
 # 2 I was tempted to take a bite of it.
 # 3 But this seemed like a bad idea...
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/helper-files/helper-3.txt"
+cat -n "$path"
\ No newline at end of file
diff --git a/individual-shell-tools/cat/script-04-stretch.sh b/individual-shell-tools/cat/script-04-stretch.sh
index 00fe3c48..73640a35 100755
--- a/individual-shell-tools/cat/script-04-stretch.sh
+++ b/individual-shell-tools/cat/script-04-stretch.sh
@@ -13,3 +13,5 @@ set -euo pipefail
 # 3 It looked delicious.
 # 4 I was tempted to take a bite of it.
 # 5 But this seemed like a bad idea...
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/helper-files"
+cat "$path"/*.txt | cat -n
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-01.sh b/individual-shell-tools/grep/script-01.sh
index fb05f42f..54169a1c 100755
--- a/individual-shell-tools/grep/script-01.sh
+++ b/individual-shell-tools/grep/script-01.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output every line in dialogue.txt said by the Doctor.
 # The output should contain 6 lines.
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/grep/dialogue.txt"
+grep '^Doctor:' "$path"
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-02.sh b/individual-shell-tools/grep/script-02.sh
index df6f8564..2cde17d1 100755
--- a/individual-shell-tools/grep/script-02.sh
+++ b/individual-shell-tools/grep/script-02.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output every line in dialogue.txt that contains the word Doctor (regardless of case).
 # The output should contain 9 lines.
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/grep/dialogue.txt"
+grep -i 'Doctor' "$path"
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-03.sh b/individual-shell-tools/grep/script-03.sh
index 5383fe57..38637aae 100755
--- a/individual-shell-tools/grep/script-03.sh
+++ b/individual-shell-tools/grep/script-03.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the number of lines in dialogue.txt that contain the word Doctor (regardless of case).
 # The output should be exactly the number 9.
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/grep/dialogue.txt"
+grep -i 'Doctor' "$path" | wc -l
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-04.sh b/individual-shell-tools/grep/script-04.sh
index 80ee0477..ab2566f4 100755
--- a/individual-shell-tools/grep/script-04.sh
+++ b/individual-shell-tools/grep/script-04.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output every line in dialogue.txt that does not contain the word "Hello" (regardless of case).
 # The output should contain 10 lines.
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/grep/dialogue.txt"
+grep -vi 'Hello' "$path"
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-05.sh b/individual-shell-tools/grep/script-05.sh
index 1eb53818..eb0b06cd 100755
--- a/individual-shell-tools/grep/script-05.sh
+++ b/individual-shell-tools/grep/script-05.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output every line in dialogue.txt that contains the string "cure", as well as the line before that line.
 # The output should contain two pairs of two lines of text (with a separator between them).
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/grep/dialogue.txt"
+grep -B 1 'cure' "$path"
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-06.sh b/individual-shell-tools/grep/script-06.sh
index 5670e3b6..2686fe8c 100755
--- a/individual-shell-tools/grep/script-06.sh
+++ b/individual-shell-tools/grep/script-06.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the name of every `.txt` file in this directory which contains a line of dialogue said by the Doctor.
 # The output should contain two filenames.
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/grep"
+grep -l '^Doctor:' "$path"/*.txt 
\ No newline at end of file
diff --git a/individual-shell-tools/grep/script-07.sh b/individual-shell-tools/grep/script-07.sh
index 9670ebad..a6ca13ff 100755
--- a/individual-shell-tools/grep/script-07.sh
+++ b/individual-shell-tools/grep/script-07.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output, for each `.txt` file in this directory, how many lines of dialogue the Doctor has.
 # The output should show that dialogue.txt contains 6 lines, dialogue-2.txt contains 2, and dialogue-3.txt contains 0.
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/grep/"
+grep -c '^Doctor:' "$path"*.txt | sed "s|$path||"
\ No newline at end of file
diff --git a/individual-shell-tools/ls/script-01.sh b/individual-shell-tools/ls/script-01.sh
index 241b62f5..92631c6c 100755
--- a/individual-shell-tools/ls/script-01.sh
+++ b/individual-shell-tools/ls/script-01.sh
@@ -13,3 +13,6 @@ fi
 
 # TODO: Write a command to list the files and folders in this directory.
 # The output should be a list of names including child-directory, script-01.sh, script-02.sh, and more.
+
+thisDir="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/ls"
+ls "$thisDir"
\ No newline at end of file
diff --git a/individual-shell-tools/ls/script-02.sh b/individual-shell-tools/ls/script-02.sh
index d0a5a10f..2346ae30 100755
--- a/individual-shell-tools/ls/script-02.sh
+++ b/individual-shell-tools/ls/script-02.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command which lists all of the files in the directory named child-directory.
 # The output should be a list of names: helper-1.txt, helper-2.txt, helper-3.txt.
+thisDir="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/ls/child-directory"
+ls "$thisDir"
\ No newline at end of file
diff --git a/individual-shell-tools/ls/script-03.sh b/individual-shell-tools/ls/script-03.sh
index 781216d2..f4382670 100755
--- a/individual-shell-tools/ls/script-03.sh
+++ b/individual-shell-tools/ls/script-03.sh
@@ -5,3 +5,4 @@ set -euo pipefail
 # TODO: Write a command which _recursively_ lists all of the files and folders in this directory _and_ all of the files inside those folders.
 # The output should be a list of names including: child-directory, script-01.sh, helper-1.txt (and more).
 # The formatting of the output doesn't matter.
+find .
\ No newline at end of file
diff --git a/individual-shell-tools/ls/script-04.sh b/individual-shell-tools/ls/script-04.sh
index 72f3817b..1d6bf63d 100755
--- a/individual-shell-tools/ls/script-04.sh
+++ b/individual-shell-tools/ls/script-04.sh
@@ -15,9 +15,12 @@ echo "First exercise (sorted newest to oldest):"
 
 # TODO: Write a command which lists the files in the child-directory directory, one per line, sorted so that the most recently modified file is first.
 # The output should be a list of names in this order, one per line: helper-3.txt, helper-1.txt, helper-2.txt.
-
+thisDir="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/ls/child-directory"
+ls -1t "$thisDir"
 
 echo "Second exercise (sorted oldest to newest):"
 
 # TODO: Write a command which does the same as above, but sorted in the opposite order (oldest first).
 # The output should be a list of names in this order, one per line: helper-2.txt, helper-1.txt, helper-3.txt.
+thisDir="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/ls/child-directory"
+ls -1tr "$thisDir"
\ No newline at end of file
diff --git a/individual-shell-tools/sed/script-01.sh b/individual-shell-tools/sed/script-01.sh
index 3eba6fa4..ed6ca0f0 100755
--- a/individual-shell-tools/sed/script-01.sh
+++ b/individual-shell-tools/sed/script-01.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # TODO: Write a command to output input.txt with all occurrences of the letter `i` replaced with `I`.
 # The output should contain 11 lines.
 # The first line of the output should be: "ThIs Is a sample fIle for experImentIng with sed.".
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/sed/input.txt"
+sed 's/i/I/g' $path
\ No newline at end of file
diff --git a/individual-shell-tools/sed/script-02.sh b/individual-shell-tools/sed/script-02.sh
index abdd64d0..cdd2432c 100755
--- a/individual-shell-tools/sed/script-02.sh
+++ b/individual-shell-tools/sed/script-02.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # TODO: Write a command to output input.txt with numbers removed.
 # The output should contain 11 lines.
 # Line 6 of the output should be " Alisha".
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/sed/input.txt"
+sed "s/[0-9]//g" $path
\ No newline at end of file
diff --git a/individual-shell-tools/sed/script-03.sh b/individual-shell-tools/sed/script-03.sh
index dd284a29..11b1e827 100755
--- a/individual-shell-tools/sed/script-03.sh
+++ b/individual-shell-tools/sed/script-03.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output input.txt removing any line which contains a number.
 # The output should contain 6 lines.
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/sed/input.txt"
+sed "/[0-9]/d" $path
\ No newline at end of file
diff --git a/individual-shell-tools/sed/script-04.sh b/individual-shell-tools/sed/script-04.sh
index 0052ac6c..cf3a2301 100755
--- a/individual-shell-tools/sed/script-04.sh
+++ b/individual-shell-tools/sed/script-04.sh
@@ -4,3 +4,7 @@ set -euo pipefail
 
 # TODO: Write a command to output input.txt replacing every occurrence of the string "We'll" with "We will".
 # The output should contain 11 lines.
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/sed/input.txt"
+old="We'll"
+new="We will"
+sed "s/$old/$new/g" $path
\ No newline at end of file
diff --git a/individual-shell-tools/sed/script-05.sh b/individual-shell-tools/sed/script-05.sh
index 2dcc91a0..922d14b5 100755
--- a/individual-shell-tools/sed/script-05.sh
+++ b/individual-shell-tools/sed/script-05.sh
@@ -6,3 +6,5 @@ set -euo pipefail
 # If a line starts with a number and a space, make the line instead end with a space and the number.
 # So line 6 which currently reads "37 Alisha" should instead read "Alisha 37".
 # The output should contain 11 lines.
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/sed/input.txt"
+sed -E 's/^([0-9]+) (.*)/\2 \1/' $path
\ No newline at end of file
diff --git a/individual-shell-tools/sed/script-06.sh b/individual-shell-tools/sed/script-06.sh
index 0b939017..82de1099 100755
--- a/individual-shell-tools/sed/script-06.sh
+++ b/individual-shell-tools/sed/script-06.sh
@@ -8,3 +8,5 @@ set -euo pipefail
 # The output should contain 11 lines.
 # Line 3 should be "It contains many lines, and there are some things you may want to do with each of them.".
 # Line 11 should be "We also should remember, when we go shopping, to get 4 items: oranges, cheese, bread, olives.".
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/sed/input.txt"
+sed -E 's/, ?/, /g' $path
\ No newline at end of file
diff --git a/individual-shell-tools/wc/script-01.sh b/individual-shell-tools/wc/script-01.sh
index c9dd6e5d..acc39b8d 100755
--- a/individual-shell-tools/wc/script-01.sh
+++ b/individual-shell-tools/wc/script-01.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the number of words in the file helper-files/helper-3.txt.
 # The output should include the number 19. The output should not include the number 92.
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/helper-files/helper-3.txt"
+wc -w "$path"
\ No newline at end of file
diff --git a/individual-shell-tools/wc/script-02.sh b/individual-shell-tools/wc/script-02.sh
index 8feeb1a6..32a6cb5d 100755
--- a/individual-shell-tools/wc/script-02.sh
+++ b/individual-shell-tools/wc/script-02.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the number of lines in the file helper-files/helper-3.txt.
 # The output should include the number 3. The output should not include the number 19.
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/helper-files/helper-3.txt"
+wc -l "$path"
\ No newline at end of file
diff --git a/individual-shell-tools/wc/script-03.sh b/individual-shell-tools/wc/script-03.sh
index 6b2e9d3d..cf4fc6b7 100755
--- a/individual-shell-tools/wc/script-03.sh
+++ b/individual-shell-tools/wc/script-03.sh
@@ -8,3 +8,5 @@ set -euo pipefail
 #        1       7      39 ../helper-files/helper-2.txt
 #        3      19      92 ../helper-files/helper-3.txt
 #        5      30     151 total
+path="/Users/cyf/Documents/SDC/Module-Tools/individual-shell-tools/helper-files"
+wc "$path"/*.txt
\ No newline at end of file
diff --git a/number-systems/README.md b/number-systems/README.md
index 77a3bde9..328312ba 100644
--- a/number-systems/README.md
+++ b/number-systems/README.md
@@ -5,61 +5,61 @@ Do not convert any binary numbers to decimal when solving a question unless the
 The goal of these exercises is for you to gain an intuition for binary numbers. Using tools to solve the problems defeats the point.
 
 Convert the decimal number 14 to binary.
-Answer:
+Answer:1110
 
 Convert the binary number 101101 to decimal:
-Answer:
+Answer:45
 
 Which is larger: 1000 or 0111?
-Answer:
+Answer:1000
 
 Which is larger: 00100 or 01011?
-Answer:
+Answer:01011
 
 What is 10101 + 01010?
-Answer:
+Answer:11111
 
 What is 10001 + 10001?
-Answer:
+Answer:100010
 
 What's the largest number you can store with 4 bits, if you want to be able to represent the number 0?
-Answer:
+Answer:15 or 0b1111
 
 How many bits would you need in order to store the numbers between 0 and 255 inclusive?
-Answer:
+Answer:8 bits (255 in base 2 is 0b11111111)
 
 How many bits would you need in order to store the numbers between 0 and 3 inclusive?
-Answer:
+Answer:2 bits (3 in base 2 is 0b11)
 
 How many bits would you need in order to store the numbers between 0 and 1000 inclusive?
-Answer:
+Answer:10 bits (1000 in base 2 is 0b1111101000)
 
 How can you test if a binary number is a power of two (e.g. 1, 2, 4, 8, 16, ...)?
-Answer:
+Answer:a binary number is a power of 2 if it has exactly one "1" bit in its representation.
 
 Convert the decimal number 14 to hex.
-Answer:
+Answer:E
 
 Convert the decimal number 386 to hex.
-Answer:
+Answer:182
 
 Convert the hex number 386 to decimal.
-Answer:
+Answer:902
 
 Convert the hex number B to decimal.
-Answer:
+Answer:11
 
 If reading the byte 0x21 as a number, what decimal number would it mean?
-Answer:
+Answer:33
 
 If reading the byte 0x21 as an ASCII character, what character would it mean?
-Answer:
+Answer:!
 
 If reading the byte 0x21 as a greyscale colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
-Answer:
+Answer:Dark shade of gray
 
 If reading the bytes 0xAA00FF as an RGB colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
-Answer:
+Answer:(RGB 170, 0, 255) high red, no green, maximum blue.
 
 If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be?
-Answer:
+Answer:170, 0, 255
diff --git a/shell-pipelines/ls-grep/script-01.sh b/shell-pipelines/ls-grep/script-01.sh
index 8c7d968a..b802b6f4 100755
--- a/shell-pipelines/ls-grep/script-01.sh
+++ b/shell-pipelines/ls-grep/script-01.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the names of the files in the sample-files directory whose name contains at least one upper case letter.
 # Your output should contain 11 files.
+path="/Users/cyf/Documents/SDC/Module-Tools/shell-pipelines/ls-grep/sample-files"
+ls $path | grep '[A-Z]'
\ No newline at end of file
diff --git a/shell-pipelines/ls-grep/script-02.sh b/shell-pipelines/ls-grep/script-02.sh
index 16f5f71d..902862d3 100755
--- a/shell-pipelines/ls-grep/script-02.sh
+++ b/shell-pipelines/ls-grep/script-02.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the names of the files in the sample-files directory whose name starts with an upper case letter.
 # Your output should contain 10 files.
+path="/Users/cyf/Documents/SDC/Module-Tools/shell-pipelines/ls-grep/sample-files"
+ls $path | grep '^[A-Z]'
\ No newline at end of file
diff --git a/shell-pipelines/ls-grep/script-03.sh b/shell-pipelines/ls-grep/script-03.sh
index a302ab03..b59fe6eb 100755
--- a/shell-pipelines/ls-grep/script-03.sh
+++ b/shell-pipelines/ls-grep/script-03.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the names of the files in the sample-files directory whose name starts with an upper case letter and doesn't contain any other upper case letters.
 # Your output should contain 7 files.
+path="/Users/cyf/Documents/SDC/Module-Tools/shell-pipelines/ls-grep/sample-files"
+ls $path | grep '^[A-Z][^A-Z]*$'
\ No newline at end of file
diff --git a/shell-pipelines/ls-grep/script-04.sh b/shell-pipelines/ls-grep/script-04.sh
index c000b7e3..22c2bb84 100755
--- a/shell-pipelines/ls-grep/script-04.sh
+++ b/shell-pipelines/ls-grep/script-04.sh
@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to count the number of files in the sample-files directory whose name starts with an upper case letter and doesn't contain any other upper case letters.
 # Your output should be the number 7.
+path="/Users/cyf/Documents/SDC/Module-Tools/shell-pipelines/ls-grep/sample-files"
+ls $path | grep -c '^[A-Z][^A-Z]*$'
\ No newline at end of file
diff --git a/shell-pipelines/sort-uniq-head-tail/script-01.sh b/shell-pipelines/sort-uniq-head-tail/script-01.sh
index 171e1f98..72f7047a 100755
--- a/shell-pipelines/sort-uniq-head-tail/script-01.sh
+++ b/shell-pipelines/sort-uniq-head-tail/script-01.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # The input for this script is the scores-table.txt file.
 # TODO: Write a command to output scores-table.txt, with lines sorted by the person's name.
 # The first line of your output should be "Ahmed London 1 10 4" (with no quotes). And the third line should be "Chandra Birmingham 12 6".
+path="/Users/cyf/Documents/SDC/Module-Tools/shell-pipelines/sort-uniq-head-tail/scores-table.txt"
+sort -t ' ' -k1 $path
\ No newline at end of file
diff --git a/shell-pipelines/sort-uniq-head-tail/script-02.sh b/shell-pipelines/sort-uniq-head-tail/script-02.sh
index 29c3c252..c2b3e164 100755
--- a/shell-pipelines/sort-uniq-head-tail/script-02.sh
+++ b/shell-pipelines/sort-uniq-head-tail/script-02.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # The input for this script is the scores-table.txt file.
 # TODO: Write a command to output scores-table.txt, with lines sorted by the person's first score, descending.
 # The first line of your output should be "Basia London 22 9 6" (with no quotes).
+path="/Users/cyf/Documents/SDC/Module-Tools/shell-pipelines/sort-uniq-head-tail/scores-table.txt"
+sort -t ' ' -k3 -n -r $path
\ No newline at end of file
diff --git a/shell-pipelines/sort-uniq-head-tail/script-03.sh b/shell-pipelines/sort-uniq-head-tail/script-03.sh
index bcbaf342..6399590e 100755
--- a/shell-pipelines/sort-uniq-head-tail/script-03.sh
+++ b/shell-pipelines/sort-uniq-head-tail/script-03.sh
@@ -8,3 +8,5 @@ set -euo pipefail
 # Basia London 22 9 6
 # Piotr Glasgow 15 2 25 11 8
 # Chandra Birmingham 12 6
+path="/Users/cyf/Documents/SDC/Module-Tools/shell-pipelines/sort-uniq-head-tail/scores-table.txt"
+sort -t ' ' -k3 -n -r $path | head -n 3
\ No newline at end of file
diff --git a/shell-pipelines/sort-uniq-head-tail/script-04.sh b/shell-pipelines/sort-uniq-head-tail/script-04.sh
index 65a5cfba..b168d95a 100755
--- a/shell-pipelines/sort-uniq-head-tail/script-04.sh
+++ b/shell-pipelines/sort-uniq-head-tail/script-04.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # The input for this script is the scores-table.txt file.
 # TODO: Write a command to output scores-table.txt, with shows the line for the player whose first score was the second highest.
 # Your output should be: "Piotr Glasgow 15 2 25 11 8" (without quotes).
+path="/Users/cyf/Documents/SDC/Module-Tools/shell-pipelines/sort-uniq-head-tail/scores-table.txt"
+sort -t ' ' -k3 -n -r $path | awk 'NR==2'
\ No newline at end of file
diff --git a/shell-pipelines/sort-uniq-head-tail/script-05.sh b/shell-pipelines/sort-uniq-head-tail/script-05.sh
index a93cd9f9..de651244 100755
--- a/shell-pipelines/sort-uniq-head-tail/script-05.sh
+++ b/shell-pipelines/sort-uniq-head-tail/script-05.sh
@@ -6,3 +6,5 @@ set -euo pipefail
 # TODO: Write a command to show a list of all events that have happened, without duplication.
 # The order they're displayed doesn't matter, but we never want to see the same event listed twice.
 # Your output should contain 6 lines.
+path="/Users/cyf/Documents/SDC/Module-Tools/shell-pipelines/sort-uniq-head-tail/events.txt"
+sort $path | uniq
\ No newline at end of file
diff --git a/shell-pipelines/sort-uniq-head-tail/script-06.sh b/shell-pipelines/sort-uniq-head-tail/script-06.sh
index 715c7ae5..24c9ee6d 100755
--- a/shell-pipelines/sort-uniq-head-tail/script-06.sh
+++ b/shell-pipelines/sort-uniq-head-tail/script-06.sh
@@ -5,3 +5,5 @@ set -euo pipefail
 # The input for this script is the events.txt file.
 # TODO: Write a command to show how many times anyone has entered and exited.
 # It should be clear from your script's output that there have been 5 Entry events and 4 Exit events.
+path="/Users/cyf/Documents/SDC/Module-Tools/shell-pipelines/sort-uniq-head-tail/events.txt"
+grep -oE 'Entry|Exit' $path | sort | uniq -c
\ No newline at end of file
diff --git a/shell-pipelines/sort-uniq-head-tail/script-07.sh b/shell-pipelines/sort-uniq-head-tail/script-07.sh
index 7fd07e1f..3868d43b 100755
--- a/shell-pipelines/sort-uniq-head-tail/script-07.sh
+++ b/shell-pipelines/sort-uniq-head-tail/script-07.sh
@@ -6,3 +6,5 @@ set -euo pipefail
 # TODO: Write a command to show how many times anyone has entered and exited.
 # It should be clear from your script's output that there have been 5 Entry events and 4 Exit events.
 # The word "Event" should not appear in your script's output.
+path="/Users/cyf/Documents/SDC/Module-Tools/shell-pipelines/sort-uniq-head-tail/events-with-timestamps.txt"
+grep -oE 'Entry|Exit' $path | sort | uniq -c
\ No newline at end of file
diff --git a/shell-pipelines/tr/script-01.sh b/shell-pipelines/tr/script-01.sh
index 8bb0211e..01c47b66 100755
--- a/shell-pipelines/tr/script-01.sh
+++ b/shell-pipelines/tr/script-01.sh
@@ -6,3 +6,5 @@ set -euo pipefail
 # The author got feedback that they're using too many exclamation marks (!).
 #
 # TODO: Write a command to output the contents of text.txt with every exclamation mark (!) replaced with a full-stop (.).
+path="/Users/cyf/Documents/SDC/Module-Tools/shell-pipelines/tr/text.txt"
+cat $path | tr '!' '.'
\ No newline at end of file
diff --git a/shell-pipelines/tr/script-02.sh b/shell-pipelines/tr/script-02.sh
index cf3a503a..8f8713d8 100755
--- a/shell-pipelines/tr/script-02.sh
+++ b/shell-pipelines/tr/script-02.sh
@@ -7,3 +7,5 @@ set -euo pipefail
 # so every Y should be a Z, and every Z should be a Y!
 #
 # TODO: Write a command to output the contents of text.txt with every Y and Z swapped (both upper and lower case).
+path="/Users/cyf/Documents/SDC/Module-Tools/shell-pipelines/tr/text.txt"
+cat $path | tr 'YZyz' 'ZYzy'
\ No newline at end of file