One day a store sold 28 sweatshirts. White ones cost $9.95 and yellow ones cost $13.50. In all, $321.20 worth of sweatshirts were sold. How many of each color were sold?

1 Answer
Nov 20, 2016

The store sold 16 white and 12 yellow sweatshirts.

Explanation:

Let's call the number of white sweatshirts sold w and the number of yellow sweatshirts sold y. Because we know there were a total of 28 sweatshirts sold we can write:

w+y=28

Solving for w gives:

w+yy=28y

w=28y

We also know and can write:

9.95w+13.50y=321.20

From the first equation we can substitute 28y for w in the second equation and solve for y

9.95(28y)+13.50y=321.20

278.69.95y+13.50y=321.20

278.6+3.55y=321.20

278.6+3.55y278.6=321.20278.6

3.55y=42.6

3.55y3.55=42.63.55

y=12

We can now substitute 12 for y in the solution to the first equation and calculate w:

w=2812

w=16