SOLUTION: 12.Mr. Coyne has some dimes and quarters. He has twice as many dimes as quarters. The total value of his coins is $8.10. How many dimes does he have?

Algebra ->  Customizable Word Problem Solvers  -> Geometry -> SOLUTION: 12.Mr. Coyne has some dimes and quarters. He has twice as many dimes as quarters. The total value of his coins is $8.10. How many dimes does he have?       Log On

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Question 39034This question is from textbook
: 12.Mr. Coyne has some dimes and quarters. He has twice as many dimes as quarters. The total value of his coins is $8.10. How many dimes does he have? This question is from textbook

Found 2 solutions by stanbon, checkley71:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Mr. Coyne has some dimes and quarters. He has twice as many dimes as quarters. The total value of his coins is $8.10. How many dimes does he have?
Let the number of quarter be "x".
Value of these quarters is 25x cents
The number of dimes is "2x"
Value of these dimes is 10(2x)=20x cents
EQUATION:
value + value = 810 cents
25x+20x=810
45x=810
x=18 (number of quarters)
2x=36 (number of dimes)
Cheers,
Stan H.

Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
810=2x*10+x*25 or 810=20x+25x or 810=45x or x=810/45 or x=18 quarters then he has 36 dimes
proof 36*10+18*25=810 or 360+450=810 or 810=810