SOLUTION: A box contains pennies, nickels, dimes, and quarters. There are twice as many nickels as pennies and 39 fewer dimes than nickels. There are as many quarters as pennies and nickels

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: A box contains pennies, nickels, dimes, and quarters. There are twice as many nickels as pennies and 39 fewer dimes than nickels. There are as many quarters as pennies and nickels       Log On


   

Question 988810: A box contains pennies, nickels, dimes, and quarters. There are twice as many nickels as pennies and 39 fewer dimes than nickels. There are as many quarters as pennies and nickels combined. If there is $390.42 in the box, then how many of each type of coin does the box contain?
Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
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N=nickels; P=pennies=0.5N; D=dimes=N-39; Q=Quarters=P+N=0.5N+N=1.5N
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$0.01P+$0.05N+$0.10D+$0.25Q=$390.42
$0.01(0.5N)+$0.05N+$0.10(N-39)+$0.25(1.5N)=$390.42
$0.005N+$0.05N+$0.10N-$3.90+$0.375N=$390.42
$0.53N=$394.32
N=744 ANSWER 1: There were 744 nickels.
P=0.5N=0.5(744)=372 ANSWER 2: There were 372 pennies.
D=N-39=744-39=705 ANSWER 3: There were 705 dimes.
Q=1.5N=1.5(744)=1116 ANSWER 4: There were 1116 quarters.
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CHECK:
$0.01P+$0.05N+$0.10D+$0.25Q=$390.42
$0.01(372)+$0.05(744)+$0.10(705)+$0.25(1116)=$390.42
$3.72+$37.20+$70.50 +$279.00=$390.42
$390.42=$390.42