SOLUTION: Karen has dimes and quarters in her pocket. The total value is $3.15. There are 7 more quarters than dimes in her pocket. How many dimes does she have? How many quarters does she h

Algebra ->  Customizable Word Problem Solvers  -> Coins -> SOLUTION: Karen has dimes and quarters in her pocket. The total value is $3.15. There are 7 more quarters than dimes in her pocket. How many dimes does she have? How many quarters does she h      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 589340: Karen has dimes and quarters in her pocket. The total value is $3.15. There are 7 more quarters than dimes in her pocket. How many dimes does she have? How many quarters does she have?
Answer by nyc_function(2741) About Me  (Show Source):
You can put this solution on YOUR website!
Let x = dimes
Let x + 7 = quarters
We multiply the value of a dime which is 10 by x to get 10x.
We also multiply the value of a quarter which is 25 by (x + 7) to get
25(x + 7).

10x + 25(x + 7) = 315
10x + 25x + 175 = 315
35x + 175 = 315
35x = 315 - 175
35x = 140
x = 140/35
x = 4
There are 4 dimes.
The amount of quarters is 7 more than 4 or 11.
The Prove:
We know that 4 dimes = 40 cents.
We also know that 11 quarters = 2.75.
So, 2.75 + 0.40 = 3.15
Did you follow?