A bag contains 7 green and 8 white balls. If two balls are drawn simultaneously, the probability that both are of the same colour is ?  Pick
A) 7/19 B) 7/15 C) 7/16 D) 7/12 E) 7/11
Drawing two balls of same color from seven green balls can be done in ⁷C₂ ways.   Similarly from eight white balls two can be drawn in ⁸C₂ ways.   P = 7C2/15C2 + 8C2/15C2 = 7/15   Answer: 7/15
<result>B</result>
A bag contains 7 green and 8 white balls. If two balls are drawn simultaneously, the probability that both are of the same colour is ?