diff --git a/exercises/count_pattern_test.rb b/exercises/test/count_pattern_test.rb
similarity index 69%
rename from exercises/count_pattern_test.rb
rename to exercises/test/count_pattern_test.rb
index 6ad7121..ef0ea75 100644
--- a/exercises/count_pattern_test.rb
+++ b/exercises/test/count_pattern_test.rb
@@ -17,51 +17,68 @@ def test_count_numbers_greater_than_17
     numbers = [9, 18, 12, 17, 1, 3, 99]
     tally = 0
     numbers.each do |number|
-      # Your code goes here
+      tally += 1 if number > 17
     end
     assert_equal 2, tally
   end
 
   def test_count_words_that_are_uppercase
-    skip
+
     words = ["trousers", "SOCKS", "sweater", "Cap", "SHOE", "TIE"]
     tally = 0
-    # Your code goes here
+    words.each do |word|
+      tally += 1 if word.upcase == word
+    end
     assert_equal 3, tally
   end
 
   def test_count_words_ending_in_ing
-    skip
+
     words = ["thought", "brake", "shin", "juice", "trash"]
-    # Your code goes here
+    tally = 0
+    words.each do |word|
+      tally +=1 if word.end_with?('ing')
+    end
     assert_equal 0, tally
   end
 
   def test_count_even_numbers
-    skip
+
     numbers = [9, 2, 1, 3, 18, 39, 71, 4, 6]
-    # Your code goes here
+    tally = 0
+    numbers.each do |number|
+      tally +=1 if number.even?
+    end
     assert_equal 4, tally
   end
 
   def test_count_multiples_of_5
-    skip
+
     numbers = [2, 5, 19, 25, 35, 67]
-    # Your code goes here
+    tally = 0
+    numbers.each do |number|
+      tally +=1 if number % 5 == 0
+    end
     assert_equal 3, tally
   end
 
   def test_count_round_prices
-    skip
+
     prices = [1.0, 3.9, 5.99, 18.5, 20.0]
-    # Your code goes here
+    tally = 0
+    prices.each do |price|
+      tally +=1 if (price - price.floor) == 0
+    end
     assert_equal 2, tally
   end
 
   def test_count_four_letter_words
-    skip
+
     words = ["bake", "bark", "corn", "apple", "wart", "bird", "umbrella", "fart"]
-    # Your code goes here
+    tally = 0
+    words.each do |word|
+      tally +=1 if word.length == 4
+    end
     assert_equal 6, tally
   end
 
diff --git a/exercises/count_test.rb b/exercises/test/count_test.rb
similarity index 73%
rename from exercises/count_test.rb
rename to exercises/test/count_test.rb
index 43a57a9..599309e 100644
--- a/exercises/count_test.rb
+++ b/exercises/test/count_test.rb
@@ -15,50 +15,62 @@ def test_count_count_words_with_e
   def test_count_numbers_greater_than_17
     numbers = [9, 18, 12, 17, 1, 3, 99]
     tally = numbers.count do |number|
-      # Your code goes here
+      number > 17
     end
     assert_equal 2, tally
   end
 
   def test_count_words_that_are_uppercase
-    skip
+
     words = ["trousers", "SOCKS", "sweater", "Cap", "SHOE", "TIE"]
-    # Your code goes here
+    tally = words.count do |word|
+      word.upcase ==  word
+    end
     assert_equal 3, tally
   end
 
   def test_count_words_ending_in_ing
-    skip
+
     words = ["thought", "brake", "shin", "juice", "trash"]
-    # Your code goes here
+    tally = words.count do |word|
+      word.end_with?('ing')
+    end
     assert_equal 0, tally
   end
 
   def test_count_even_numbers
-    skip
+
     numbers = [9, 2, 1, 3, 18, 39, 71, 4, 6]
-    # Your code goes here
+    tally = numbers.count do |number|
+      number.even?
+    end
     assert_equal 4, tally
   end
 
   def test_count_multiples_of_5
-    skip
+
     numbers = [2, 5, 19, 25, 35, 67]
-    # Your code goes here
+    tally = numbers.count do |number|
+      number % 5 == 0
+    end
     assert_equal 3, tally
   end
 
   def test_count_round_prices
-    skip
+
     prices = [1.0, 3.9, 5.99, 18.5, 20.0]
-    # Your code goes here
+    tally = prices.count do |price|
+      price - price.floor == 0
+    end
     assert_equal 2, tally
   end
 
   def test_count_four_letter_words
-    skip
+
     words = ["bake", "bark", "corn", "apple", "wart", "bird", "umbrella", "fart"]
-    # Your code goes here
+    tally = words.count do |word|
+      word.length == 4
+    end
     assert_equal 6, tally
   end
 
diff --git a/exercises/find_pattern_test.rb b/exercises/test/find_pattern_test.rb
similarity index 60%
rename from exercises/find_pattern_test.rb
rename to exercises/test/find_pattern_test.rb
index 13f3319..0171c8f 100644
--- a/exercises/find_pattern_test.rb
+++ b/exercises/test/find_pattern_test.rb
@@ -20,65 +20,115 @@ def test_no_waldo
     words = ["scarf", "sandcastle", "flag", "pretzel", "crow", "key"]
     found = nil
     words.each do |word|
-      # Your code goes here
+      if word == 'waldo'
+        found = 'waldo'
+        break
+      end
     end
     assert_equal nil, found
   end
 
   def test_find_waldo
-    skip
+
     words = ["noise", "dog", "fair", "house", "waldo", "bucket", "fish"]
     found = nil
-    # Your code goes here
+    words.each do |word|
+      if word == 'waldo'
+        found = 'waldo'
+        break
+      end
+    end
     assert_equal "waldo", found
   end
 
   def test_cannot_find_3_letter_words
-    skip
+
     words = ["piglet", "porridge", "bear", "blueberry"]
-    # Your code goes here
+    found = nil
+    words.each do |word|
+      if word.length == 3
+        found = word
+        break
+      end
+    end
     assert_equal nil, found
   end
 
   def test_find_13
-    skip
+
     numbers = [2, 13, 19, 8, 3, 27]
-    # Your code goes here
+    found = nil
+    numbers.each do |number|
+      if number == 13
+        found = 13
+        break
+      end
+    end
     assert_equal 13, found
   end
 
   def test_find_first_even_number
-    skip
+
     numbers = [3, 7, 13, 11, 10, 2, 17]
-    # Your code goes here
+    found = nil
+    numbers.each do |number|
+      if number.even?
+        found = number
+        break
+      end
+    end
     assert_equal 10, found
   end
 
   def test_find_first_multiple_of_3
-    skip
+
     numbers = [2, 8, 9, 27, 24, 5]
-    # Your code goes here
+    found = nil
+    numbers.each do |number|
+      if number % 3 == 0
+        found = number
+        break
+      end
+    end
     assert_equal 9, found
   end
 
   def test_find_first_word_starting_with_q
-    skip
+
     words = ["weirdo", "quill", "fast", "quaint", "quitter", "koala"]
-    # Your code goes here
+    found = nil
+    words.each do |word|
+      if word.start_with? 'q'
+        found = word
+        break
+      end
+    end
     assert_equal "quill", found
   end
 
   def test_find_first_word_ending_with_er
-    skip
+
     words = ["biggest", "pour", "blight", "finger", "pie", "border"]
-    # Your code goes here
+    found = nil
+    words.each do |word|
+      if word.end_with? 'er'
+        found = word
+        break
+      end
+    end
     assert_equal "finger", found
   end
 
   def test_find_first_number_greater_than_20
-    skip
+
     numbers = [1, 8, 19, 21, 29, 31, 34]
-    # Your code goes here
+    found = nil
+    numbers.each do |number|
+      if number > 20
+        found = number
+        break
+      end
+    end
     assert_equal 21, found
   end
 
diff --git a/exercises/find_test.rb b/exercises/test/find_test.rb
similarity index 73%
rename from exercises/find_test.rb
rename to exercises/test/find_test.rb
index 61c2d71..940602c 100644
--- a/exercises/find_test.rb
+++ b/exercises/test/find_test.rb
@@ -15,64 +15,79 @@ def test_find_first_seven_letter_word
   def test_no_waldo
     words = ["scarf", "sandcastle", "flag", "pretzel", "crow", "key"]
     found = words.find do |word|
-      # Your code goes here
+      word == 'waldo'
     end
     assert_equal nil, found
   end
 
   def test_find_waldo
-    skip
     words = ["noise", "dog", "fair", "house", "waldo", "bucket", "fish"]
-    # Your code goes here
+    found = words.find do |word|
+      word == 'waldo'
+    end
     assert_equal "waldo", found
   end
 
   def test_cannot_find_3_letter_words
-    skip
+
     words = ["piglet", "porridge", "bear", "blueberry"]
-    # Your code goes here
+    found = words.find do |word|
+      word.length == 3
+    end
     assert_equal nil, found
   end
 
   def test_find_13
-    skip
+
     numbers = [2, 13, 19, 8, 3, 27]
-    # Your code goes here
+    found = numbers.find do |number|
+      number == 13
+    end
     assert_equal 13, found
   end
 
   def test_find_first_even_number
-    skip
+
     numbers = [3, 7, 13, 11, 10, 2, 17]
-    # Your code goes here
+    found = numbers.find do |number|
+      number.even?
+    end
     assert_equal 10, found
   end
 
   def test_find_first_multiple_of_3
-    skip
+
     numbers = [2, 8, 9, 27, 24, 5]
-    # Your code goes here
+    found = numbers.find do |number|
+      number % 3 == 0
+    end
     assert_equal 9, found
   end
 
   def test_find_first_word_starting_with_q
-    skip
+
     words = ["weirdo", "quill", "fast", "quaint", "quitter", "koala"]
-    # Your code goes here
+    found = words.find do |word|
+      word.start_with? 'q'
+    end
     assert_equal "quill", found
   end
 
   def test_find_first_word_ending_with_er
-    skip
+
     words = ["biggest", "pour", "blight", "finger", "pie", "border"]
-    # Your code goes here
+    found = words.find do |word|
+      word.end_with? 'er'
+    end
     assert_equal "finger", found
   end
 
   def test_find_first_number_greater_than_20
-    skip
+
     numbers = [1, 8, 19, 21, 29, 31, 34]
-    # Your code goes here
+    found = numbers.find do |number|
+      number > 20
+    end
     assert_equal 21, found
   end
 
diff --git a/exercises/map_pattern_test.rb b/exercises/test/map_pattern_test.rb
similarity index 71%
rename from exercises/map_pattern_test.rb
rename to exercises/test/map_pattern_test.rb
index c54279b..e31dfe7 100644
--- a/exercises/map_pattern_test.rb
+++ b/exercises/test/map_pattern_test.rb
@@ -17,51 +17,68 @@ def test_doubles
     numbers = [1, 2, 3, 4, 5]
     doubles = []
     numbers.each do |number|
-      # Your code goes here
+      doubles << number * 2
     end
     assert_equal [2, 4, 6, 8, 10], doubles
   end
 
   def test_squares
-    skip
+
     numbers = [1, 2, 3, 4, 5]
     squares = []
-    # Your code goes here
+    numbers.each do |number|
+      squares << number * number
+    end
     assert_equal [1, 4, 9, 16, 25], squares
   end
 
   def test_lengths
-    skip
+
     names = ["alice", "bob", "charlie", "david", "eve"]
-    # Your code goes here
+    lengths = []
+    names.each do |name|
+      lengths << name.length
+    end
     assert_equal [5, 3, 7, 5, 3], lengths
   end
 
   def test_normalize_zip_codes
-    skip
+
     numbers = [234, 10, 9119, 38881]
-    # Your code goes here
+    zip_codes = []
+    numbers.each do |number|
+      zip_codes << number.to_s.rjust(5, '0')
+    end
     assert_equal ["00234", "00010", "09119", "38881"], zip_codes
   end
 
   def test_backwards
-    skip
+
     names = ["alice", "bob", "charlie", "david", "eve"]
-    # Your code goes here
+    backwards = []
+    names.each do |name|
+      backwards << name.reverse
+    end
     assert_equal ["ecila", "bob", "eilrahc", "divad", "eve"], backwards
   end
 
   def test_words_with_no_vowels
-    skip
+
     words = ["green", "sheep", "travel", "least", "boat"]
-    # Your code goes here
+    without_vowels = []
+    words.each do |word|
+      without_vowels << word.delete('aeiou')
+    end
     assert_equal ["grn", "shp", "trvl", "lst", "bt"], without_vowels
   end
 
   def test_trim_last_letter
-    skip
+
     animals = ["dog", "cat", "mouse", "frog", "platypus"]
-    # Your code goes here
+    trimmed = []
+    animals.each do |animal|
+      trimmed << animal.chop
+    end
     assert_equal ["do", "ca", "mous", "fro", "platypu"], trimmed
   end
 
diff --git a/exercises/map_test.rb b/exercises/test/map_test.rb
similarity index 74%
rename from exercises/map_test.rb
rename to exercises/test/map_test.rb
index 8f502c1..1f7f805 100644
--- a/exercises/map_test.rb
+++ b/exercises/test/map_test.rb
@@ -1,6 +1,7 @@
 gem 'minitest'
 require 'minitest/autorun'
 require 'minitest/pride'
+require 'pry'
 
 class MapTest < Minitest::Test
 
@@ -15,50 +16,64 @@ def test_capitalize
   def test_doubles
     numbers = [1, 2, 3, 4, 5]
     doubles = numbers.map do |number|
-      # Your code goes here
+      number * 2
     end
     assert_equal [2, 4, 6, 8, 10], doubles
   end
 
   def test_squares
-    skip
+
     numbers = [1, 2, 3, 4, 5]
-    # Your code goes here
+    squares = numbers.map do |number|
+      number * number
+    end
     assert_equal [1, 4, 9, 16, 25], squares
   end
 
   def test_lengths
-    skip
+
     names = ["alice", "bob", "charlie", "david", "eve"]
-    # Your code goes here
+    lengths = names.map do |name|
+      name.length
+    end
     assert_equal [5, 3, 7, 5, 3], lengths
   end
 
   def test_normalize_zip_codes
-    skip
+
     numbers = [234, 10, 9119, 38881]
-    # Your code goes here
+    zip_codes = numbers.map do |number|
+      number.to_s.rjust(5, '0')
+    end
+
     assert_equal ["00234", "00010", "09119", "38881"], zip_codes
   end
 
   def test_backwards
-    skip
+
     names = ["alice", "bob", "charlie", "david", "eve"]
-    # Your code goes here
+    backwards = names.map do |name|
+      name.reverse
+    end
     assert_equal ["ecila", "bob", "eilrahc", "divad", "eve"], backwards
   end
 
   def test_words_with_no_vowels
-    skip
+
     words = ["green", "sheep", "travel", "least", "boat"]
-    # Your code goes here
+
+    without_vowels = words.map do |word|
+      word.delete('aeiou')
+    end
     assert_equal ["grn", "shp", "trvl", "lst", "bt"], without_vowels
   end
 
   def test_trim_last_letter
-    skip
+
     animals = ["dog", "cat", "mouse", "frog", "platypus"]
-    # Your code goes here
+    trimmed = animals.map do |animal|
+      animal.chop
+    end
     assert_equal ["do", "ca", "mous", "fro", "platypu"], trimmed
   end
 
diff --git a/exercises/select_pattern_test.rb b/exercises/test/select_pattern_test.rb
similarity index 68%
rename from exercises/select_pattern_test.rb
rename to exercises/test/select_pattern_test.rb
index 6628eac..87b890e 100644
--- a/exercises/select_pattern_test.rb
+++ b/exercises/test/select_pattern_test.rb
@@ -17,72 +17,98 @@ def test_pick_odd_numbers
     numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
     odds = []
     numbers.each do |number|
-      # Your code goes here
+      odds << number if number.odd?
     end
     assert_equal [1, 3, 5, 7, 9], odds
   end
 
   def test_pick_words_with_three_letters
-    skip
+
     words = ["pill", "bad", "finger", "cat", "blue", "dog", "table", "red"]
     selected = []
-    # Your code goes here
+    words. each do |word|
+      selected << word if word.length == 3
+    end
     assert_equal ["bad", "cat", "dog", "red"], selected
   end
 
   def test_pick_words_with_more_than_three_letters
-    skip
+
     words = ["pill", "bad", "finger", "cat", "blue", "dog", "table", "red"]
-    # Your code goes here
+    selected = []
+    words.each do |word|
+      selected << word if word.length > 3
+    end
     assert_equal ["pill", "finger", "blue", "table"], selected
   end
 
   def test_pick_words_ending_in_e
-    skip
+
     words = ["are", "you", "strike", "thinking", "belt", "piece", "warble", "sing", "pipe"]
-    # Your code goes here
+    selected = []
+    words.each do |word|
+      selected << word if word.end_with? 'e'
+    end
     assert_equal ["are", "strike", "piece", "warble", "pipe"], selected
   end
 
   def test_pick_words_ending_in_ing
-    skip
+
     words = ["bring", "finger", "drought", "singing", "bingo", "purposeful"]
-    # Your code goes here
+    selected = []
+    words.each do |word|
+      selected << word if word.end_with? 'ing'
+    end
     assert_equal ["bring", "singing"], selected
   end
 
   def test_pick_words_containing_e
-    skip
+
     words = ["four", "red", "five", "blue", "pizza", "purple"]
-    # Your code goes here
+    selected = []
+    words.each do |word|
+      selected << word if word.include? 'e'
+    end
     assert_equal ["red", "five", "blue", "purple"], selected
   end
 
   def test_pick_dinosaurs
-    skip
+
     animals = ["tyrannosaurus", "narwhal", "eel", "achillesaurus", "qingxiusaurus"]
-    # Your code goes here
+    dinosaurs = []
+    animals.each do |animal|
+      dinosaurs << animal if animal.end_with? 'saurus'
+    end
     assert_equal ["tyrannosaurus", "achillesaurus", "qingxiusaurus"], dinosaurs
   end
 
   def test_pick_floats
-    skip
+
     numbers = [3, 1.4, 3.5, 2, 4.9, 9.1, 8.0]
-    # Your code goes here
+    floats = []
+    numbers.each do |number|
+      floats << number if number.is_a?(Float)      #also works !number.integer?
+    end
     assert_equal [1.4, 3.5, 4.9, 9.1, 8.0], floats
   end
 
   def test_pick_arrays
-    skip
+
     elements = ["CAT", ["dog"], 23, [56, 3, 8], "AIMLESS", 43, "butter"]
-    # Your code goes here
+    arrays = []
+    elements.each do |element|
+      arrays << element if element.is_a?(Array)
+    end
     assert_equal [["dog"], [56, 3, 8]], arrays
   end
 
   def test_pick_hashes
-    skip
+
     elements = ["cat", {:dog=>"fido"}, 23, {:stuff=>"things"}, "aimless", 43]
-    # Your code goes here
+    hashes = []
+    elements.each do |element|
+      hashes << element if element.is_a?(Hash)
+    end
     assert_equal [{:dog=>"fido"}, {:stuff=>"things"}], hashes
   end
 
diff --git a/exercises/select_test.rb b/exercises/test/select_test.rb
similarity index 73%
rename from exercises/select_test.rb
rename to exercises/test/select_test.rb
index bdede87..ee87f85 100644
--- a/exercises/select_test.rb
+++ b/exercises/test/select_test.rb
@@ -15,71 +15,89 @@ def test_pick_even_numbers
   def test_pick_odd_numbers
     numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
     odds = numbers.select do |number|
-      # Your code goes here
+      number.odd?
     end
     assert_equal [1, 3, 5, 7, 9], odds
   end
 
   def test_pick_words_with_three_letters
-    skip
+
     words = ["pill", "bad", "finger", "cat", "blue", "dog", "table", "red"]
-    # Your code goes here
+      selected = words.select do |word|
+        word.length == 3
+      end
     assert_equal ["bad", "cat", "dog", "red"], selected
   end
 
   def test_pick_words_with_more_than_three_letters
-    skip
+
     words = ["pill", "bad", "finger", "cat", "blue", "dog", "table", "red"]
-    # Your code goes here
+      selected = words.select do |word|
+        word.length > 3
+      end
     assert_equal ["pill", "finger", "blue", "table"], selected
   end
 
   def test_pick_words_ending_in_e
-    skip
+
     words = ["are", "you", "strike", "thinking", "belt", "piece", "warble", "sing", "pipe"]
-    # Your code goes here
+    selected = words.select do |word|
+      word.end_with? 'e'
+    end
     assert_equal ["are", "strike", "piece", "warble", "pipe"], selected
   end
 
   def test_pick_words_ending_in_ing
-    skip
+
     words = ["bring", "finger", "drought", "singing", "bingo", "purposeful"]
-    # Your code goes here
+      selected = words.select do |word|
+        word.end_with? 'ing'
+      end
     assert_equal ["bring", "singing"], selected
   end
 
   def test_pick_words_containing_e
-    skip
+
     words = ["four", "red", "five", "blue", "pizza", "purple"]
-    # Your code goes here
+      selected = words.select do |word|
+        word.include? 'e'
+      end
     assert_equal ["red", "five", "blue", "purple"], selected
   end
 
   def test_pick_dinosaurs
-    skip
+
     animals = ["tyrannosaurus", "narwhal", "eel", "achillesaurus", "qingxiusaurus"]
-    # Your code goes here
+      dinosaurs = animals.select do |animal|
+        animal.end_with? 'saurus'
+      end
     assert_equal ["tyrannosaurus", "achillesaurus", "qingxiusaurus"], dinosaurs
   end
 
   def test_pick_floats
-    skip
+
     numbers = [3, 1.4, 3.5, 2, 4.9, 9.1, 8.0]
-    # Your code goes here
+      floats = numbers.select do |number|
+        number.is_a?(Float)
+      end
     assert_equal [1.4, 3.5, 4.9, 9.1, 8.0], floats
   end
 
   def test_pick_arrays
-    skip
+
     elements = ["CAT", ["dog"], 23, [56, 3, 8], "AIMLESS", 43, "butter"]
-    # Your code goes here
+      arrays = elements.select do |element|
+        element.is_a?(Array)
+      end
     assert_equal [["dog"], [56, 3, 8]], arrays
   end
 
   def test_pick_hashes
-    skip
+
     elements = ["cat", {:dog=>"fido"}, 23, {:stuff=>"things"}, "aimless", 43]
-    # Your code goes here
+      hashes = elements.select do |element|
+        element.is_a?(Hash)
+      end
     assert_equal [{:dog=>"fido"}, {:stuff=>"things"}], hashes
   end
 
diff --git a/exercises/sort_by_pattern_test.rb b/exercises/test/sort_by_pattern_test.rb
similarity index 67%
rename from exercises/sort_by_pattern_test.rb
rename to exercises/test/sort_by_pattern_test.rb
index 33d9306..61c1746 100644
--- a/exercises/sort_by_pattern_test.rb
+++ b/exercises/test/sort_by_pattern_test.rb
@@ -1,7 +1,7 @@
 gem 'minitest'
 require 'minitest/autorun'
 require 'minitest/pride'
-
+require 'pry'
 class SortByPatternTest < Minitest::Test
 
   def test_sort_alphabetically
@@ -22,7 +22,7 @@ def test_sort_alphabetically_by_last_letter
     things = ["pill", "box", "glass", "water", "sponge"]
     transformed = []
     things.each do |thing|
-      # Your code goes here
+      transformed << [thing[-1], thing]
     end
     transformed = transformed.sort
     sorted = []
@@ -33,10 +33,12 @@ def test_sort_alphabetically_by_last_letter
   end
 
   def test_sort_by_distance
-    skip
+
     distances = ["1cm", "9cm", "30cm", "4cm", "2cm"]
     transformed = []
-    # Your code goes here
+    distances.each do |distance|
+      transformed << [distance.to_i, distance]
+    end
     transformed = transformed.sort
     sorted = []
     transformed.each do |sort_key, distance|
@@ -46,24 +48,47 @@ def test_sort_by_distance
   end
 
   def test_sort_by_length
-    skip
+
     words = ["heteromorph", "ancyloceratina", "bioengineering", "mathematical", "bug"]
-    # Your code goes here
+    transformed = []
+    words.each do |word|
+      transformed << [word.length, word]
+    end
+    transformed = transformed.sort
+    sorted = []
+    transformed.each do |sort_key, word|
+      sorted << word
+    end
     assert_equal ["bug", "heteromorph", "mathematical", "ancyloceratina", "bioengineering"], sorted
   end
 
   def test_sort_by_proximity_to_ten
-    skip
+
     prices = [3.02, 9.91, 17.9, 10.01, 11.0]
-    # Your code goes here
+    transformed = []
+    prices.each do |price|
+      transformed << [(10 - price).abs, price]
+    end
+    transformed = transformed.sort
+    sorted = []
+    transformed.each do |sort_key, price|
+      sorted << price
+    end
     assert_equal [10.01, 9.91, 11.0, 3.02, 17.9], sorted
   end
 
   def test_sort_by_number_of_cents
-    skip
+
     prices = [3.02, 9.91, 7.9, 10.01, 11.0]
-    # Your code goes here
+    transformed = []
+    prices.each do |price |
+      transformed << [(price - price.floor), price]
+    end
+    transformed = transformed.sort
+    sorted = []
+    transformed.each do |sort_key, price|
+      sorted << price
+    end
     assert_equal [11.0, 10.01, 3.02, 7.9, 9.91], sorted
   end
-
 end
\ No newline at end of file
diff --git a/exercises/sort_by_test.rb b/exercises/test/sort_by_test.rb
similarity index 80%
rename from exercises/sort_by_test.rb
rename to exercises/test/sort_by_test.rb
index 91c6465..55ed6d9 100644
--- a/exercises/sort_by_test.rb
+++ b/exercises/test/sort_by_test.rb
@@ -15,36 +15,44 @@ def test_sort_alphabetically
   def test_sort_alphabetically_by_last_letter
     things = ["pill", "box", "glass", "water", "sponge"]
     sorted = things.sort_by do |thing|
-      # Your code goes here
+      thing[-1]
     end
     assert_equal ["sponge", "pill", "water", "glass", "box"], sorted
   end
 
   def test_sort_by_distance
-    skip
+
     distances = ["1cm", "9cm", "30cm", "4cm", "2cm"]
-    # Your code goes here
+    sorted = distances.sort_by do |distance|
+      distance.to_i
+    end
     assert_equal ["1cm", "2cm", "4cm", "9cm", "30cm"], sorted
   end
 
   def test_sort_by_length
-    skip
+
     words = ["heteromorph", "ancyloceratina", "bioengineering", "mathematical", "bug"]
-    # Your code goes here
+    sorted = words.sort_by do |word|
+      word.length
+    end
     assert_equal ["bug", "heteromorph", "mathematical", "ancyloceratina", "bioengineering"], sorted
   end
 
   def test_sort_by_proximity_to_ten
-    skip
+
     prices = [3.02, 9.91, 17.9, 10.01, 11.0]
-    # Your code goes here
+    sorted = prices.sort_by do |price|
+      (10 - price).abs
+    end
     assert_equal [10.01, 9.91, 11.0, 3.02, 17.9], sorted
   end
 
   def test_sort_by_number_of_cents
-    skip
+
     prices = [3.02, 9.91, 7.9, 10.01, 11.0]
-    # Your code goes here
+    sorted = prices.sort_by do |price|
+      price - price.floor
+    end
     assert_equal [11.0, 10.01, 3.02, 7.9, 9.91], sorted
   end