Question 1006932
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lisa has $3.80 worth of coins in her wallet, consisting of nickels, dimes, and quarters. 
She has twice as many nickels as dimes, and 3 times as many quarters as dimes. Write an equation that can be used to find how many of each coin Lisa has.
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5n + 10d + 25q = 380,

n = 2d,

q = 3d.

Combine it together:

5*(2d) + 10d + 25*(3d) = 380, or

10d + 10d + 75d = 380, or

95d = 380. 

Hence, d = {{{380/95}}} = 4 dimes.

Now, n = 2d = 8 nickels and q = 3d = 12 quarters.
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