SOLUTION: Monica's piggybank contains $8.55 in nickels, dimes, and quarters. The number of dimes is 5 more than 3 times the number of nickels. The number of quarters is 2 times the number of
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Question 391846: Monica's piggybank contains $8.55 in nickels, dimes, and quarters. The number of dimes is 5 more than 3 times the number of nickels. The number of quarters is 2 times the number of dimes. How many of each kind are there? Answer by Edwin McCravy(20086) (Show Source):
Monica's piggybank contains $8.55 in nickels, dimes, and quarters.
.05N + .10D + .25Q = 8.55
Multiply through by 100
5N + 10D + 25Q = 855
Divide through by 5
N + 2D + 5Q = 171
The number of dimes is 5 more than 3 times the number of nickels.
D = 3N + 5
The number of quarters is 2 times the number of dimes.
Q = 2D
Solve the system of three equations in three unknowns or variables:
N + 2D + 5Q = 171
D = 3N + 5
Q = 2D
Answer
3 nickels = $ .15
14 dimes = 1.40
28 quarters = 7.00
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total = $8.55
Edwin
