If 54= 3/5, what is _ = 2/5. All you need to do is set up a proportion as follows:: Female- 54. 3 ________. _____. = ___ Male- Blank. 2 If 3 multiplied by 18 is 54. To find the male amount, we have to multiply 2 by 18, because whatever you do to the bottom you do to the top, vise versa.