A parking meter contains dimes and quarters worth $11.75. There are 53 coins in all. Find how many each there are.

Question

A parking meter contains dimes and quarters worth $11.75. There are 53 coins in all. Find how many of each there are.

Answer 1

Hi Skyler, let d represent the dimes and q represent the quarters. Create two equations representing the known information.

 

Equation 1, number of coins:

 

d + q = 53

 

Equation 2, amount of coins:

 

.10d + .25q = 53

 

Solve using a system of equations:

 

     d +      q  = 53

.10d + .25q  = 11.75

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Multiply equation 1 by -.10

 

-.10d  - .10q  = -.10 * 53

 .10d + .25q  = 11.75

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           .15q = 6.45

 

               q = 43

 

There are 43 quarters.

 

Using equation 1:

 

d + 43 = 53

 

d = 10

 

There are 10 dimes.

 

Questions?