Cedrick lives in a city with 6% sales tax. He uses the formula below to calculate the total cost, c, of a purchase amount, p, including sales tax:

c = 1.06p

Cedrick purchases 2 bottles of perfume for gifts, one for his mother and one for his sister, at $30 each. What is the total cost, including sales tax?

$3.60

$31.80

$61.06

$63.60

Incorrect. This is the amount of sales tax that Cedrick will pay.
Incorrect. Cedrick purchased 2 bottles of perfume. Recalculate the purchase amount.
Incorrect. The formula says to multiply 1.06 by the purchase amount.
Correct. The purchase amount was $60, and the total cost is $63.60.