Question

One day a store sold 30 sweatshirts. White ones cost $11.95 and yellow ones cost $12.50. In all, $364.00 worth of sweatshirts were sold. How many of each color were sold?

Answer 1

There were 10 yellow and 20 white sweatshirts sold by the store.

Explanation:

Let's call the white sweatshirts `w` and the yellow ones `y`.

Then we can say:

`w + y = 30` and `11.95w + 12.50y = 364`

Solve the first equation for `w` while keeping the equation balanced:

`w + y - y= 30 - y`

`w = 30 - y`

Substitute `30 - y` into the second equation for `w` and solve for `y` while keeping the equation balanced:

#11.95(30 - y) + 12.50y = 364.

`358.5 - 11.95y + 12.50y = 364`

`358.5 + 0.55y = 364`

`358.5 - 0.55y - 358.5 = 364 - 358.5`

`0.55y = 5.5`

`(0.55y)/0.55 = 5.5/0.55`

`y = 10`

Substitute `10` for `y` in the result of the first equation and solve for `w`

`w = 30 - 10`

`w = 20`