Question

One day a store sold 27 sweatshirts. White ones cost $11.95 and yellow ones cost $12.50. In all, $331.45 worth of sweatshirts were sold. How many of each color were sold?

Answer 1

There are 16 yellow and 11 white sweatshirts

Explanation:

Let the count of yellow sweatshirts be `y`
Let the count of white sweatshirts be `w`

As such we are given that
`w+y=27`

Subtract y from both sides

`w=27-y`........................Equation(1)
`color(white)(.)`

.............................................................................
Also given: `[wxx$11.95]+[yxx$12.50] = $331.45`

Drop the $ sign

`[color(red)(w)xx11.95]+[yxx12.50] = 331.45`................Equation(2)

...........................................................................

Substitute for `color(red)(w)` in equation(2) using equation(1)

`[color(red)((27-y))xx11.95]+12.5y=331.45`

`322.65-11.95y" "+12.5y=331.45`

`322.65+0.55y=331.45`

`0.55y=331.45-322.65`

`0.55y=8.8`

`y=8.8/.55=16`
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Substitute for `w` in equation(1)

`w=27-y" "->" "w=27-16`

w=11#
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There are 16 yellow and 11 white sweatshirts