Question 614118
Do it like this:  2 methods are shown.
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Diane has $1.15 in dimes and nickels. She has a total of 13 coins. How many of each kind does she have?
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A different method:
If she had 13 dimes it would be $1.30
Each dime replaced by a nickel is a loss of $0.05
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130 - 115 = 15 cents
15/5 --> 3 nickels
10 dimes 
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Answer 386356 by edjones(7477)   on 2012-05-23 08:05:04 (Show Source): 

You can put this solution on YOUR website!
Let d=number of dimes and n=number of nickels.
d+n=13
.1d+.05n=1.15
.
d=13-n
.1(13-n)+.05n=1.15
1.3-.1n+.05n=1.15
-.05n=-.15
n=3
d=10