there are 4 red shoes & 6 green shoes . if two of red shoes are drawn what is the probability of getting red shoes
"taking 4 red shoe the probablity is 4 c 2 from 10 shoes probablity of taking 2 red shoe is 4 c 2 / 10 c 2 = 2 / 15 answer : d"
divide(choose(4, const_2), choose(add(4, 6), const_2))