how many positive integers less than 5,000 are evenly divisible by neither 17 nor 21 ?
"integers less than 5000 divisible by 17 5000 / 17 = 333 . something , so 333 integers less than 5000 divisible by 21 5000 / 21 = 238 . # # , so 238 we have double counted some , so take lcm of 17 and 21 = 105 and divide by 5000 , we get 47 . so all numbers divisible by 17 and 21 = 333 + 238 - 47 = 524 now subtract that from 4999 . 4999 - 524 = 4480 answer b ."
divide(factorial(subtract(add(const_4, 17), const_1)), multiply(factorial(17), factorial(subtract(const_4, const_1))))