so what you got to do is divide them perseay use a calculator for the first one 2/15 what would that be in a decimal 0.13333333333333 what ever on has 0.13333333 or something else repeating that is the one that you will circle 11/20=0.55 17/40 =0.425 1/2=0.5 so you answer would be 2/15
hope this helped