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8 quarters make exactly 2 dollars.
Take off 8 quarters from your collection.
Then rest of coins in the collection are equal amounts of quarters and dimes, and the updated collection is worth $3.50 = 350 cents.
Group them in pairs, one dime and one quarter in each pair. Then each pair is worth 10 + 25 = 35 cents.
Hence, he number of the pairs is 10.
Hence, there are 10 quarters and 10 dimes in the updated collection.
Now return back those 8 quarters, you took away in the beginning.
Answer. There are 10 dimes and 18 quarter in the original collection.
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There is entire bunch of lessons on coin problems
- 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
- Three methods for solving standard (typical) coin word problems
- More complicated coin problems
- Solving coin problems mentally by grouping without using equations
- Santa Claus helps solving coin problem
- OVERVIEW of lessons on coin word problems
in this site.
You will find there the lessons for all levels - from introductory to advanced,
and for all methods used - from one equation to two equations and even without equations.
Read them and become an expert in solution of coin problems.
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".
Save the link to this online textbook together with its description
Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson
to your archive and use it when it is needed.