A bag contains 6 red, 3 yellow and 4 green balls. 3 balls are drawn randomly. What is the probability that the balls drawn contain balls of different colours?	Choose the correct option:	A) 2/7	B) 3/5	C) 3/11	D) 1/4	E) 7/16
Total number of balls = 6+3+4= 
<gadget id="calculator">6+3+4</gadget>
<output>13</output>
13   n(S)= 13C3 = 286   n(E) = 6C1 * 3C1 * 4C1 = 72   Probability = 72/286 = 1/4   Answer is 1/4
<result>D</result>
A bag contains 6 red, 3 yellow and 4 green balls. 3 balls are drawn randomly. What is the probability that the balls drawn contain balls of different colours?