I assume the question is asking how much he paid...?
If so, he has 10% off from 100% of the original price. 100% - 10% means he will pay 90% of the original price. To find the original price we must add the price of the two items together to get the total price.
$93 + $13.99 = (I will let you do the math.)
Then we must multiply the total price by the percentage he paid (90%). To do this we must convert 90% into a decimal. Percent(%) is just a way of saying "Out of 100". So 90/100 = .90
For the final answer multiply: .90 * total price = answer.