A bag contains 9 green and 8 white balls. If two balls are drawn simultaneously, the probability that both are of the same colour is
Select the correct option
A) 8 / 17
B) 2 / 5
C) 3 / 5
D) 11 / 15
E) 7 / 15

Rationale: "drawing two balls of same color from nine green balls can be done in 9 c ₂ ways . similarly from eight white balls two can be drawn in ⁸ c ₂ ways . p = 9 c ₂ / ¹ ⁵ c ₂ + ⁸ c ₂ / ¹ ⁵ c ₂ = 8 / 17 answer : a"
Answer: A