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?  Pick one
A) 2/7  B) 3/5  C) 3/11  D) 1/4  E) 7/16
Total number of balls = 3+5+4= 
<gadget id="calculator">3+5+4</gadget>
<output>12</output>
12   n(S)= 123/113 = 12*11*10 / 3*2 = 220   n(E) = 33/111 * 53/111 * 43/111 = 3*5* 4= 
<gadget id="calculator">3*5* 4</gadget>
<output>60</output>
60   Probability= 60/220 = 3/11   Answer is 3/11
<result>C</result>
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?