diff --git a/session1/3-challenge/1_arithmetic.rb b/session1/3-challenge/1_arithmetic.rb
index 049ece773..30c55e232 100644
--- a/session1/3-challenge/1_arithmetic.rb
+++ b/session1/3-challenge/1_arithmetic.rb
@@ -9,5 +9,9 @@
 # arithmetic1(-6)     # => -50
 
 def arithmetic1(n)
-  
+<<<<<<< HEAD
+  n-20*5
+=======
+  n * 5 - 20
+>>>>>>> 83101f98e8bd2cec234ee9dbfbaf32fb6469153c
 end
diff --git a/session1/3-challenge/2_arithmetic.rb b/session1/3-challenge/2_arithmetic.rb
index 21445b427..eff1269a0 100644
--- a/session1/3-challenge/2_arithmetic.rb
+++ b/session1/3-challenge/2_arithmetic.rb
@@ -9,4 +9,5 @@
 # arithmetic2(-6, -7)  # => -3.5
 
 def arithmetic2(a, b)
+  a > b ? b / 2.0 : a / 2.0
 end
diff --git a/session1/3-challenge/3_simple_logic.rb b/session1/3-challenge/3_simple_logic.rb
index 29f8c5037..67e5196af 100644
--- a/session1/3-challenge/3_simple_logic.rb
+++ b/session1/3-challenge/3_simple_logic.rb
@@ -8,4 +8,6 @@
 # ten_twenty(6) # => 10
 
 def ten_twenty(n)
+n.odd? ? 20 : 10
+
 end
diff --git a/session1/3-challenge/5_string.rb b/session1/3-challenge/5_string.rb
index ed15e87ad..43c53104e 100644
--- a/session1/3-challenge/5_string.rb
+++ b/session1/3-challenge/5_string.rb
@@ -1,8 +1,9 @@
 # Given a string, replace every instance of sad to happy
-# 
+#
 # add_more_ruby("The clowns were sad.")         # => "The clowns were happy."
 # add_more_ruby("The sad dad said sad stuff.")  # => "The happy dad said happy stuff."
 # add_more_ruby("Sad times are ahead!")         # => "Happy times are ahead!"
 
 def add_more_ruby(string)
-end
\ No newline at end of file
+  string.gsub(/[sS]ad/, {'sad' =>'happy', 'Sad'=>'Happy'})
+end
diff --git a/session1/3-challenge/6_string.rb b/session1/3-challenge/6_string.rb
index 4dc3a4e83..ab48b0ae7 100644
--- a/session1/3-challenge/6_string.rb
+++ b/session1/3-challenge/6_string.rb
@@ -6,5 +6,13 @@
 #
 
 def odds_and_evens(string, return_odds)
+new_string = ""
+string.length.times do |x|
+next if return_odds == true && x.even?
+next if return_odds == false && x.odd?
 
-end
\ No newline at end of file
+new_string << string[x]
+end
+
+new_string
+end
diff --git a/session2/3-challenge/12_classes.rb b/session2/3-challenge/12_classes.rb
index 7bc1f194a..78a2c6bdc 100644
--- a/session2/3-challenge/12_classes.rb
+++ b/session2/3-challenge/12_classes.rb
@@ -23,8 +23,34 @@
 # f.to_f               # => 0.5
 
 class Fraction
+
+  attr_accessor :numerator, :denominator
+
+  def initialize numerator, denominator
+    @numerator = numerator
+    @denominator = denominator
+    
+  end
+
   def gcd(a,b)
     return a if b == 0
     gcd(b, a%b)
   end
+
+  def to_s 
+    "#{@numerator}/#{@denominator}"
+  end
+
+  def to_f
+    @numerator / denominator.to_f 
+  end
+
+  def lowest
+    div = gcd(@denominator, @numerator) 
+    Fraction.new(@numerator/div, @denominator/div)
+  end
 end
+
+f = Fraction.new(20,60)
+puts f.numerator
+puts f.lowest.to_s
\ No newline at end of file
diff --git a/session2/3-challenge/1_input_output.rb b/session2/3-challenge/1_input_output.rb
index 99f723341..5538eac06 100644
--- a/session2/3-challenge/1_input_output.rb
+++ b/session2/3-challenge/1_input_output.rb
@@ -8,6 +8,11 @@
 # "11\n7\n18\n" to standard output.
 
 def sum_difference_product
-  # your code goes here
-  
-end
\ No newline at end of file
+  # num = gets.chomp
+  numbers = gets.chomp.split(" ")
+  puts numbers[0].to_i + numbers[1].to_i
+  puts numbers[0].to_i - numbers[1].to_i
+  puts numbers[0].to_i * numbers[1].to_i
+
+
+end
diff --git a/session2/3-challenge/2_input_output_control.rb b/session2/3-challenge/2_input_output_control.rb
index 31ce263ee..8679ceb66 100644
--- a/session2/3-challenge/2_input_output_control.rb
+++ b/session2/3-challenge/2_input_output_control.rb
@@ -19,8 +19,17 @@
 # and when you think it is correct, you can test it with  $ rake 2:2
 
 def hi_hi_goodbye
-  # your code here
-
+  puts "Enter a number"
+  while true
+    number = gets.chomp
+    break if number == "bye"
+    number.to_i.times  do
+      print "hi "
+    end
+    puts ""
+    # number.to_i.times print "hi "
+  end
+puts "goodbye"
 end
 
 
@@ -29,4 +38,4 @@ def hi_hi_goodbye
 # This will just invoke the method if you run this program directly
 # This way you can try it out by running "$ ruby 2_input_output_control.rb"
 # but it will still work for our tests
-hi_hi_goodbye if $0 == __FILE__
\ No newline at end of file
+hi_hi_goodbye if $0 == __FILE__
diff --git a/session2/3-challenge/3_array.rb b/session2/3-challenge/3_array.rb
index 4dea8459c..d36da3195 100644
--- a/session2/3-challenge/3_array.rb
+++ b/session2/3-challenge/3_array.rb
@@ -7,6 +7,18 @@
 
 class String
   def every_other_char
+    str = ""
+    split_string = self.split("")
+    count = 1
+    split_string.each do |letter|
+      if count % 2 == 1
+        str += letter
+      end
+      count += 1
+    end
+
+    str
   end
-  
 end
+
+puts "sdfsdfsdf".every_other_char
diff --git a/session2/3-challenge/4_array.rb b/session2/3-challenge/4_array.rb
index 85602ab21..3ffeb0949 100644
--- a/session2/3-challenge/4_array.rb
+++ b/session2/3-challenge/4_array.rb
@@ -8,5 +8,14 @@
 
 # This time you will have to define the method, it's called: get_squares
 
+def get_squares(num_arr)
+  return_arr = []
+  num_arr.each do |number|
+    if num_arr.include?(number * number)
+      return_arr << number
+    end
+  end
+return_arr.sort
+end
 
-
+# puts get_squares([9,3,81])
diff --git a/session2/3-challenge/5_array.rb b/session2/3-challenge/5_array.rb
index 3f1125b04..47f27f661 100644
--- a/session2/3-challenge/5_array.rb
+++ b/session2/3-challenge/5_array.rb
@@ -14,3 +14,10 @@
 #
 # mod_three [0,1,2,3,4,5,6,7] # => [1, 2, 1, 2, 1]
 
+def mod_three(num_arr)
+  new = []
+  num_arr.map {|number| new << number  % 3 if number % 3 > 0}
+new
+end
+
+puts mod_three([3,4,5,6,7,8,9])
diff --git a/session2/3-challenge/6_array.rb b/session2/3-challenge/6_array.rb
index 90ae4534c..773539029 100644
--- a/session2/3-challenge/6_array.rb
+++ b/session2/3-challenge/6_array.rb
@@ -15,3 +15,13 @@
 # prime_chars? ['a', 'bcd']       # => false
 # prime_chars? ['a', 'b', 'cd']   # => false
 
+def prime_chars?(num_arr)
+require 'prime'
+total = 0
+  num_arr.each do |x|
+    total +=  x.length
+  end
+Prime.prime?(total)
+end
+
+# puts prime_chars?(["s"])
diff --git a/session2/3-challenge/9_input_output_logic_string.rb b/session2/3-challenge/9_input_output_logic_string.rb
index 626119b35..f2baf2860 100644
--- a/session2/3-challenge/9_input_output_logic_string.rb
+++ b/session2/3-challenge/9_input_output_logic_string.rb
@@ -24,7 +24,15 @@
 # USER:     BYE
 
 def deaf_grandma
-
+while true
+  input = gets.chomp
+  break if input == "BYE"
+  if input == input.upcase && input != ""
+    puts "NO, NOT SINCE 1938!"
+  else
+    puts "HUH?! SPEAK UP, SONNY!"
+  end
+end
 end