Question 380481
Joe has a collection of nickels and dimes that is worth $6.00. If the number of dimes was doubled and the number of nickels was increased by 6, the value of the coins would be $9.90. How many dimes does he have?
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Value Eq: 5n + 10d = 600 cents
Value Eq: 5(n+6)+10(2d) = 990 cents
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Rearrange and modify to get:
5n+ 20d = 990-30
5n+ 10d = 600
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Subtract bottom from top and solve for "d":
10d = 360
d = 36 (# of dimes)
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Substitute and solve for "n":
5n+10*36 = 600
5n+360 = 600
5n = 240
n = 48 (# of nickels)
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Cheers,
stan H.