Aaron borrowed $500 at 16% annual interest rate for 12 months under an add-on-plan. How much does he have to repay?
You just gotta figure out what 16% of 500 is.
500 * .16 = 80
Aaron must repay $80.
Actually he needs to repay $580 as he still has to repay the initial $500 but now also the $80 he accrued in interest.