Problem: each factor of 240 is inscribed on its own plastic ball , and all of the balls are placed in a jar . if a ball is randomly selected from the jar , what is the probability that the ball is inscribed with a multiple of 15 ?
Rationale: "the # of factors 240 has is 20 ; so out of 20 factors only four are multiples of 15 : 15 , 30 , 60 , 120 and 240 , itself ; so , the probability is 5 / 20 = 1 / 4 . answer : e ."
annotated_formula: divide(divide(choose(15, const_1), 15), power(const_3, const_2))