Calculate $18 for 4 shirts or $25 for 5 shirts

Step by step

The question

Question: which is the better buy, A: $18 for 4 shirts, or B: $25 for 5 shirts?

The amounts are different, so we can't just look at the prices.

We find the price for 1 shirt in each deal.

1 Write both as fractions

We write each deal as a fraction.

The money goes on top.

The shirts go on the bottom.

2 Divide to get 1 at the bottom

We want 1 shirt on the bottom.

In A, we divide the top and the bottom by 4.

In B, we divide them by 5.

18 divided by 4 is 4.5.

25 divided by 5 is 5.

So A is 4 dollars and 50 cents per shirt.

B is 5 dollars per shirt.

3 Compare

4 dollars and 50 cents is less than 5 dollars.

Deal A costs less for each shirt.

So deal A is the better buy.

Let's look back.

First: write both as fractions.

Then: divide to get 1 at the bottom.

Last: compare.