Question 662999: I have $1 in coins. One-fifth of the coins are dimes, two-fifteenths are nickels, and two-thirds are pennies. How many of each coin do I have?
I know that I have 30 coins with 6 dimes, 4 nickels and 20 pennies. I can't seem to figure out an equation to show how I arrived at my answer.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! I have $1 in coins. One-fifth of the coins are dimes, two-fifteenths are nickels, and two-thirds are pennies. How many of each coin do I have?
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Note: (1/5) + (2/15) + (2/3) = (3/15) + (2/15) + (10/15) = 15/15 = 1
Equations:
Value Equation: p + 5n + 10d = 100 cents
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Let "x" be the number of coins.
p = (2/3)x
n = (2/15)x
d = (1/5)x
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Substitute and solve for "x"
(2/3)x + 5(2/15)x + 10(1/5)x = 100
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Multiply thru by 15:
10x + 10x + 30x = 1500
50x = 1500
x = 30 (total # of coins)
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Cheers,
Stan H.
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