if n is the product of integers from 1 to 20 inclusive what is the greatest integer k for which 2 ^ k is a factor of n ?
"given : n = 20 ! n = 20 ! . the highest power k for which 2 ^ k is a factor of n can be found with the above formula : k = 20 / 2 + 20 / 4 + 20 / 8 + 20 / 16 = 10 + 5 + 2 + 1 = 18 answer : d ."
add(add(add(divide(20, 2), divide(20, power(2, 2))), floor(divide(20, power(power(2, 2), 2)))), floor(divide(20, power(2, const_3))))