A bag contains 3 red, 6 yellow and 8 green balls. 3 balls are drawn randomly. What is the probability that the balls drawn contain balls of different colours? Answers:
A) 2/7	B) 3/5	C) 3/11	D) 18/85	E) 7/16
Total number of balls = 3+6+8= 
<gadget id="calculator">3+6+8</gadget>
<output>17</output>
17   n(S)= 17C3 = 680   n(E) = 3C1 * 6C1 * 8C1 = 144   Probability = 144/680 = 18/85   Answer is 18/85
<result>D</result>
A bag contains 3 red, 6 yellow and 8 green balls. 3 balls are drawn randomly. What is the probability that the balls drawn contain balls of different colours?