SOLUTION: A piggy bank contains only quarters and nickels, and there is a total of 60 coins. The total value of the coins is $7.40, so how many coins are there?

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Question 1150878: A piggy bank contains only quarters and nickels, and there is a total of 60 coins. The total value of the coins is $7.40, so how many coins are there?
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!


let quarters be q and nickels n
value of the coins is: q=$0.25 and n=$0.05
given:
there is a total of 60 coins, so
q%2Bn=60
q=60-n ...........eq.1
The total value of the coins is $7.40, so
0.25q%2B0.05n=7.40 .......substitute q from eq.1
0.25%2860-n%29%2B0.05n=7.40.........solve for n
15-0.25n%2B0.05n=7.40
15-0.20n=7.40
15-7.40=+0.20n
7.60=+0.20n
n=7.60%2F+0.20
n=38
then
q=60-n ...........eq.1
q=60-38
q=22

so, there are 22 quarters and 38 nickels

check:
0.25q%2B0.05n=7.40
0.25%2A22%2B0.05%2A38=7.40
5.50%2B1.90=7.40
7.40=7.40