if 15 ! / 3 ^ x is an integer , what is the greatest possible value of x ?
"15 - 5 * 3 12 - 4 * 3 9 - 3 * 3 6 - 2 * 3 3 - 1 * 3 hence max of 3 ^ 6 is allowed . imo d ."
add(divide(15, 3), divide(3, divide(15, 3)))