In a carton there are balls of 10 different colors. What is the least number of balls that you have to take out so that you will have a matching pair?(Assuming that all the balls are of same size but different colors)  Choose the correct choice from the following options:
A) 12
B) 6
C) 9
D) 11
E) 15
Since there are 10 colors, if you take 10 balls, you could still have 1 ball per color and not have a match.   Therefore, upon taking the 11th ball, you will definitely have a match since the 11th ball will form at least a pair with the 1st 10   So 10+1= 
<gadget id="calculator">10+1</gadget>
<output>11</output>
11   Answer is 11
<result>D</result>
In a carton there are balls of 10 different colors. What is the least number of balls that you have to take out so that you will have a matching pair?(Assuming that all the balls are of same size but different colors)