Question

robert brought a used car for $15,00.00 if the sales tax is 5% what will be the total that robert had to pay for the car

Answer 1

15,000 x .05 = 750
750 + 15,000 = 15,750
$15,750 is the total Robert paid for the used car.

Answer 2

With sales tax, just multiply the price by the sales tax divided by one hundred with one added.
15,000•1.05
15,750
The price he had to pay was 15,750.