Problem: there are 3 red shoes & 7 green shoes . if two of red shoes are drawn what is the probability of getting red shoes
Rationale: "taking 2 red shoe the probablity is 3 c 2 from 10 shoes probablity of taking 2 red shoe is 3 c 2 / 10 c 2 = 1 / 15 answer : d"
annotated_formula: divide(choose(3, const_2), choose(add(3, 7), const_2))