SOLUTION: In a collection of nickels and dimes the number of dimes is 3 more than twice the number of nickels. If the value of the collection is $1.80, how many coins are there?

Question 104837: In a collection of nickels and dimes the number of dimes is 3 more than twice the number of nickels. If the value of the collection is $1.80, how many coins are there?
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!
n = number of nickels
d = number of dimes
value of one nickel is 5 cents, so the value of n nickels is 5n cents
value of one dime is 10 cents, so the value of d dimes is 10d cents
The number of dimes (d) is (=) 3 more (+3) than twice the number of nickels (2n), so

The value of the collection, that is the value of the dimes plus the value of the nickels is $1.80 or 180 cents, so

Substitute the expression for d from the first equation into the second equation:

Simplify and solve:

So there are coins.

Check:

and
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