Answer: $22.61
Step-by-step explanation: A 25% discount means that instead of paying the full value, you will pay 25% less. So the total price you will pay for a CD of $32.99:
P₁ = 32.99 * (1 - 0.25)
P₁ = 32.99 * (0.75)
P₁ = 24.7425
However, you still have a discount of 15% over the price, so:
P₂ = 24.7425 * (1 - 0.15)
P₂ = 24.7425 * (0.85)
P₂ = 21.03
The sales tax is a value incorporated over the price after all the discounts:
P = 21.03 * (1 + 0.075)
P = 21.03 * (1.075)
P = 22.61
The total final price for the CD is $22.61.