a bag contains 5 green balls and 9 white balls . if two balls are drawn simultaneously , what is the probability that both balls are the same colour ?
"the total number of ways to draw two balls is 14 c 2 = 91 the number of ways to draw two green balls is 5 c 2 = 10 the number of ways to draw two white balls is 9 c 2 = 36 p ( two balls of the same colour ) = 46 / 91 the answer is d ."
add(multiply(divide(9, add(5, 9)), divide(subtract(9, const_1), subtract(add(5, 9), const_1))), multiply(divide(subtract(5, const_1), subtract(add(5, 9), const_1)), divide(5, add(5, 9))))