diff --git a/2015/20151209 - animal game - ruby/animal_game.rb b/2015/20151209 - animal game - ruby/animal_game.rb
index 2d72e17e..811d74f4 100644
--- a/2015/20151209 - animal game - ruby/animal_game.rb	
+++ b/2015/20151209 - animal game - ruby/animal_game.rb	
@@ -1,9 +1,12 @@
 def prize(value, bet, drawed)
-  verifier = bet % 100 - 1
+  bet    = bet % 100
   drawed = drawed % 100
-  drawed = 99 if drawed == 0
 
-  return value * 16 if verifier / 4 == drawed / 4
+  bet    = 100 if bet == 0
+  drawed = 100 if drawed == 0
+
+  return value * 50 if bet == drawed
+  return value * 16 if (bet - 1) / 4 == (drawed - 1) / 4
   
   0
 end
\ No newline at end of file
diff --git a/2015/20151209 - animal game - ruby/animal_game_spec.rb b/2015/20151209 - animal game - ruby/animal_game_spec.rb
index 23b02c7d..8643ade7 100644
--- a/2015/20151209 - animal game - ruby/animal_game_spec.rb	
+++ b/2015/20151209 - animal game - ruby/animal_game_spec.rb	
@@ -5,36 +5,52 @@
     expect(prize(1, 1234, 0)).to eq(0)
   end
 
-  it "gives 16x value if is from same group 1" do
-    expect(prize(1, 1299, 0)).to eq(16)
-  end
+  context "gives 16x value if is from same group" do
+    it "1" do
+      expect(prize(1, 1299, 0)).to eq(16)
+    end
 
-  it "gives 16x value if is from same group 2" do
-    expect(prize(2, 1299, 0)).to eq(32)
-  end
+    it "2" do
+      expect(prize(2, 1299, 0)).to eq(32)
+    end
 
-  it "gives 16x value if is from same group 3" do
-    expect(prize(2, 1297, 0)).to eq(32)
-  end
+    it "3" do
+      expect(prize(2, 1297, 0)).to eq(32)
+    end
 
-  it "gives 16x value if is from same group 4" do
-    expect(prize(2, 1201, 2)).to eq(32)
-  end
+    it "4" do
+      expect(prize(2, 1201, 2)).to eq(32)
+    end
 
-  it "gives 16x value if is from same group 5" do
-    expect(prize(2, 1205, 7)).to eq(32)
-  end
+    it "5" do
+      expect(prize(2, 1205, 7)).to eq(32)
+    end
 
-  it "gives 16x value if is from same group 6" do
-    expect(prize(2, 1205, 3)).to eq(0)
-  end
+    it "6" do
+      expect(prize(2, 1205, 3)).to eq(0)
+    end
+
+    it "7" do
+      expect(prize(2, 3405, 3)).to eq(0)
+    end
+
+    it "8" do
+      expect(prize(2, 3405, 1206)).to eq(32)
+    end
+
+    it "9" do
+      expect(prize(2, 1200, 5601)).to eq(0)
+    end
 
-  it "gives 16x value if is from same group 6" do
-    expect(prize(2, 3405, 3)).to eq(0)
+    it "10" do
+      expect(prize(2, 1200, 5699)).to eq(32)
+    end
   end
 
-  it "gives 16x value if is from same group 6" do
-    expect(prize(2, 3405, 1206)).to eq(32)
+  context "gives 50x if last 2 digits are equal" do
+    it "1" do
+      expect(prize(2, 1299, 5699)).to eq(100)
+    end
   end
 
 end
\ No newline at end of file
diff --git a/2015/20151209 - animal game - ruby/dojo.log b/2015/20151209 - animal game - ruby/dojo.log
index f86682b1..b656f4a6 100644
--- a/2015/20151209 - animal game - ruby/dojo.log	
+++ b/2015/20151209 - animal game - ruby/dojo.log	
@@ -2,3 +2,4 @@ Qua Dez 9 19:32:36 BRST 2015 - Toti Cavalcanti e Otavio Cardoso
 Qua Dez 9 19:46:15 BRST 2015 - Otavio Cardoso e Toti Cavalcanti
 Qua Dez 9 19:54:55 BRST 2015 - Toti Cavalcanti e Otavio Cardoso
 Qua Dez 9 20:02:24 BRST 2015 - Otavio Cardoso e Toti Cavalcanti
+Qua Dez 9 20:10:08 BRST 2015 - Toti Cavalcanti e Otavio Cardoso