Question 515197: a person has 50 coins in dimes and quarters with a combined value of $7.70. Determine the number of coins of each type Answer by oberobic(2304) (Show Source):
You can put this solution on YOUR website! d = number of dimes
10d = value of dimes in cents
q = number of quarters
25q = value of quarters in cents
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10d + 25q = 770 cents
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d + q = 50
so
d = 50-q
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substitute.
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10(50-q) + 25q = 770
500 - 10q +25q = 770
15q = 270
q = 18
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d = 50-q
d = 32
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Check the values to make sure they're right.
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25*18 = 450
10*32 = 320
Total = 770
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Answer: The person has 18 quarters and 32 dimes.
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Done.
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