SOLUTION: Andy has 21 coins made up of quarters and half dollars, and their total value is $6.50. How many quarters does he have?

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Question 274991: Andy has 21 coins made up of quarters and half dollars, and their total value is $6.50. How many quarters does he have?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let q = number of quarters
Let h = number of half dollars
---------------------
given:
(1) h+%2B+q+=+21
(2) 50h+%2B+25q+=+650 (in cents)
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Multiply both sides of (1) by 25
and subtract from (2)
(2) 50h+%2B+25q+=+650%7D%0D%0A%281%29+%7B%7B%7B-25h+-+25q+=+525
25h+=+125
h+=+5
And, since
(1) h+%2B+q+=+21
5+%2B+q+=+21
q+=+16
There are 16 quarters and 5 half dollars
check:
(2) 50h+%2B+25q+=+650
50%2A5+%2B+25%2A16+=+650
250+%2B+400+=+650
650+=+650
OK