# Find the replacement for ?

624  -->   20
532  -->  117
634  -->  152
723  -->   40
443  -->  175
825  -->   ?


What should be filled in the last place so as to maintain the logical pattern?

$39$
$6^2 - 4^2 = 20$
$5^3 - 2^3 = 117$
$6^3 - 4^3 = 152$
$7^2 - 3^2 = 40$
$4^4 - 3^4 = 175$
$8^2 - 5^2 = 39$