SOLUTION: In a jar of coins, there are 30 fewer quarters than dimes. The value of the dimes equals the value of the quarters. How many dimes are in the jar.

Question 1074054: In a jar of coins, there are 30 fewer quarters than dimes. The value of the dimes equals the value of the quarters. How many dimes are in the jar.

Answer by ikleyn(52887) (Show Source): You can put this solution on YOUR website!
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From the condition, you have these two equations

Q = D -30,    (1)

10D = 25Q.    (2)


Substitute (1) into (2), and you will get

10D = 25*(D - 30)  --->  10D = 25D - 750  --->  15D = 750  --->  D =  = 50.


Answer.  50 dimes and 50-30 = 20 quarters.

For coin problems and their detailed solutions see the lessons in this site:
    - Coin problems
    - More Coin problems
    - Solving coin problems without using equations
    - Kevin and Randy Muise have a jar containing coins
    - Typical coin problems from the archive
    - Solving coin problems mentally by grouping without using equations
    - Santa Claus helps solving coin problem

Read them attentively and become an expert in this field.

Also, you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this online textbook under the topic "Coin problems".

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