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?

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Answer 1 · 2016-11-17T13:36:20

There are 16 yellow and 11 white sweatshirts

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