How to Calculate Discounts on the new SAT

When Shondra makes an online purchase, a 15% discount is applied to the retail price and then a 6.25% tax is added to this discounted price. Which of the following represents the amount Shondra pays, in dollars, for an item with a retail price of x dollars?

A) x - 0.15 + 0.0625x
B) 1.0625x - 0.15x
C) 1.0625(0.85x)
D) x - 0.15(1.0625x)

Answer: C

If x represents the retail price of the order, then x - 0.15x = 0.85x is the price after the 15% discount. IF a 6.25% tax is added, the final price is 0.85x + 0.0625(0.85x) = 1.0625(0.85x).