there are 5 red shoes & 4 green shoes . if two of red shoes are drawn what is the probability of getting red shoes
taking 2 red shoe the probability is 5 c 2 from 9 shoes probability of taking 2 red shoes is 5 c 2 / 9 c 2 = 5 / 18 answer : c
divide(choose(5, const_2), choose(add(5, 4), const_2))