A game normally cost $53.00, but Isabel used a coupon and got the game for $37.10. The coupon was for what percent off.

We could use the numbers and the difference of the original cost - the end price in a equation.

53 * x/100 = 15.9

Cross multiply 100 * 15.9.

53x=1590

Divide both sides by 53.

x=30

The coupon was 30%

I think it is 30 because if you take 37.90 from 53.00 you get 15.90 and you calculate it like this:

15.90*100≈1590:53≈30%