Question

Jane has $20.00 to spend on $15.00 t-shirt and 2 pens. How much can she spend on each pen if they are both the same price?

Answer 1

Let p = cost of pens in dollars.

Jane has 20 dollars, she cannot go above this amount, so we should set up an equation.

$15.00+2p=20.00$

This equation says the fifteen dollar shirt plus the 2 pens she buys has to be equal to $20.00. Let's solve this equation to find the price of the pens. First, we must subtract 15 from both sides. When we do that, we get:

$2p=5.00$

After that, we must get p by itself, so divide both sides by 2.

$\frac{2p}{2}=\frac{5.00}{2}$

When we divide and simplify, we get:

$p=\frac{5}{2}$ or $p=2.5$

The cost of the pens are $2.50. If you want to check your work, plug in 2.50 for p.

$15.00+2(2.5)=20.00$

$15.00+5=20.00$

$20.00=20.00$

This is true. Therefore, the answer is valid.

Answer 2

$20.00 - $15.00 = $5.00

$5.00 ÷ 2 = $2.50      <==== price of a pen