SOLUTION: a collection of nickels and quarters has a total value of $6.40. If there are forty coins in the collection, how many are there of each kind?
Question 519701: a collection of nickels and quarters has a total value of $6.40. If there are forty coins in the collection, how many are there of each kind? Answer by oberobic(2304) (Show Source):
You can put this solution on YOUR website! With coin problems you have to keep track of the number of coins and their values separately.
n = number of nickels
5n = value of the nickels in cents
q = number of quarters
25q = value of the quarters in cents
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n+q = 40
n = 40-q
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5n + 25q = 640 cents
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substitute
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5(40-q) +25q = 640
200 -5q +25q = 640
20q = 440
q = 22
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n = 40-22
n = 18
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check the values to be sure this is the correct answer
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25(22) = 550 cents
5(18) = 90 cents
550 + 90 = 640 cents = $6.40
correct
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Answer: There are 22 quarters and 18 nickels.
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Done.
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