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Joe has 2 more quarters than nickels and 5 times as many nickels as dimes. Altogether he has $6.90. How many dimes does Joe have?
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Let "d" be the number of dimes.
Then the number of nickels is 5d,
and the number of quarters is (5d+2).
The dimes contribute 10d cents to the total.
The nickels contribute 5*(5d) = 25d cents to the total.
The quarters contribute 25*(5d+2) = 125d + 50 cents to the total.
Therefore, the "value" equation is
10d + 25d + 125d + 50 = 690 (cents).
Simplify and solve for d:
160d + 50 = 690,
160d = 690-40,
160d = 640 ---> d = = 4.
Answer. The number of dimes is 4. The number of nickels is 4*5 = 20. The number of quarters is 5*4+2 = 22.
Check. 5*20 + 10*4 + 22*25 = 690. Correct !
There is entire bunch of the lessons on coin problems
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- Solving coin problems without using equations
- Kevin and Randy Muise have a jar containing coins
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- OVERVIEW of lessons on coin word problems
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Read them and become an expert in solution of coin problems.
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