SOLUTION: Everyday, Lisa puts her spare change (nickels and dimes) in a piggy-bank. This weekend she decides to count her savings. She finds that she has 72 coins with a total value of $4.9

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Question 293388: Everyday, Lisa puts her spare change (nickels and dimes) in a piggy-bank. This
weekend she decides to count her savings. She finds that she has 72 coins with a total value of $4.95. How many dimes does she have?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
(nickels and dimes) in a piggy-bank. This
weekend she decides to count her savings. She finds that she has 72 coins with a total value of $4.95. How many dimes does she have?
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Quantity Equation: n + d = 72
Value Equation::: 5n+10d = 495 cents
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Multiply thru the Quantity equation by 5 to get:
5n + 5d = 5*72
5n +10d = 495
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Subtract the 1st Eq. from the 2nd and solve for "d":
5d = 495-5*72
5d = 135
d = 27 (# of dimes)
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Cheers,
Stan H.