a bag contains 6 red , 3 yellow and 4 green balls . 3 balls are drawn randomly . what is the probability that the balls drawn contain balls of different colours ?
"total number of balls = 6 + 3 + 4 = 13 n ( s ) = 13 c 3 = 286 n ( e ) = 6 c 1 * 3 c 1 * 4 c 1 = 72 probability = 72 / 286 = 1 / 4 answer is d"
divide(multiply(choose(4, const_2), choose(add(6, 3), const_1)), choose(add(add(6, 3), 4), 6))