diff --git a/evolopy/GA.py b/evolopy/GA.py
index 3a6b8c7..32b58de 100644
--- a/evolopy/GA.py
+++ b/evolopy/GA.py
@@ -181,14 +181,14 @@ def rouletteWheelSelectionId(scores, popSize):
     """
 
     ##reverse score because minimum value should have more chance of selection
-    reverse = max(scores) + min(scores)
+    reverse = max(scores)
     reverseScores = reverse - scores.copy()
     sumScores = sum(reverseScores)
     pick = random.uniform(0, sumScores)
     current = 0
     for individualId in range(popSize):
         current += reverseScores[individualId]
-        if current > pick:
+        if current >= pick:
             return individualId