Question the-co

3.2 Percentages - Discounts, markups, tax, tips
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The cost of a certain shirt is $20 before a 5% sales tax is added. What is the total cost, including sales tax, to purchase the shirt?

A.

$20.05

B.

$20.50

C.

$21.00

D.

$25.00

The cost of a certain shirt is $20 before a 5% sales tax is added. What

Medium-difficulty · SAT Math · Percentages — Discounts, markups, tax, tips. Read the question above, select your answer, and check the full explanation below to understand exactly why the correct choice works.

Answer explanation

Choice C is correct. The total cost to purchase the shirt is the $20 cost of the shirt plus the 5% sales tax. The value of the 5% sales tax on the $20 shirt is equivalent to0 point 0 5 times 20 dollars, or $1. Therefore, the total cost to purchase the shirt is 20 dollars plus 1 dollar, or $21.

Choice A is incorrect and may result from neglecting to multiply by $20 when finding the value of the sales tax. Choice B is incorrect and may result from dividing by 10, instead of by 100, and then neglecting to multiply by $20 when finding the sales tax. Choice D is incorrect and may result from interpreting the sales tax of 5% as $5.