Question

The tax rate as a percent, r, charged on an item can be determined using the formula – 1 = r, where c is the final cost of the item and p is the price of the item before tax. Louise rewrites the equation to solve for the final cost of the item: c = p(1 + ). What is the final cost of a $40 item after an 8% tax is applied?

Answer 1

P = 40
r = 8% = 8/100 = 0.08 (use the decimal form)

c = p*(1+r)
c = 40*(1+0.08)
c = 40*(1.08)
c = 43.20

The final cost (after tax) is 43.20

Answer 2

The correct answer is:

$43.20

Explanation:

The formula we have is

c = p(1+r), where c is the total cost, p is the price of the item before tax, and r is the tax rate written as a decimal.  This formula comes from the fact that adding a percent tax to the cost of an item takes 100% of the price and adds r% to it; this is why we multiply the price by (1+r).

Since our tax rate is 8%, r = 8% = 8/100 = 0.08.  The price of the item is $40.  Using this information, we have:

c = 40(1.08) = $43.20