if n is a positive integer and the product of all integers from 1 to n , inclusive , is a multiple of 420 , what is the least possible value of n ?
"420 = 2 * 2 * 3 * 5 * 7 , so n must be at least 7 . the answer is b ."
divide(divide(divide(divide(420, const_2), const_3), const_4), divide(const_10, const_2))