Question

A shopper bought a watermelon, a pack of napkins, and some paper plates. In his state, there is no tax on food. The tax rate on non-food items is 5%. The total for the three items he bought was $8.25 before tax, and he paid $0.19 in tax. How much did the watermelon cost? (Can you please explain how to solve the problem to?)

Answer 1

The watermelon costs $4.45

Explanation:

Hi there!

Let´s define the variables:

x = cost of the watermelon.

y = cost of the napkins.

z = cost of the paper plates.

We know that the sum of the 3 items costs 8.25 without taxes. Then:

x + y + z = 8.25

We also know that he paid 0.19 in total taxes and that the only items taxed at 5% are the napkins (y) and the paper plates (z). Then, 5% of the cost of the napkins plus 5% of the cost of the plates is 0.19:

0.05 y + 0.05 z = 0.19

If we divide both sides of this equation by 0.05, we will obtain:

y + z = 0.19/0.05

y + z = 3.8

Then, let´s replace y + z = 3.8 in the first equation and solve it for x:

x + y + z = 8.25 (y + z = 3.8)

x + 3.8 = 8.25

subtract 3.8 to both sides of the equation:

x = 4.45

The watermelon costs $4.45

Have a nice day!