Task: Question Answering
Input (English): Problem: a jar contains 20 red , 20 blue , 6 yellow and 4 pink balls . if two balls are to be selected at random and without replacement , approximately what is the probability both of them to be the same colour ? 
Options: a ) 1 / 25 , b ) 1 / 15 , c ) 1 / 3 , d ) 1 / 2 , e ) 1
Output (English): c