if n is the greatest positive integer for which 4 ^ n is a factor of 8 ! , then n = ?
"8 ! = 40320 e . 4 ^ 10 = 1048576 ( 40320 / 1048576 ) - this is not a factor of 8 ! d . 4 ^ 8 = 65536 ( 40320 / 65536 ) - this is not a factor of 8 ! c . 4 ^ 6 = 4096 ( 40320 / 4096 ) - this is not a factor of 8 ! b . 4 ^ 4 = 256 ( 40320 / 256 ) - this is not a factor of 8 ! a . 4 ^ 2 = 16 ( 40320 / 16 ) - this is a factor of 8 !"
subtract(divide(8, const_2), const_1)