Task: Question Answering
Input (English): Problem: a bag contains 3 red, 5 yellow and 4 green balls. 3 balls are drawn randomly. what is the probability that the balls drawn contain balls of different colours ?
Options: a. 2 / 7, b. 3 / 5, c. 3 / 11, d. 1 / 4, e. 7 / 16
Output (English): c