find how many quarters and dimes there

Question

a parking meter contains quarters and dimes worth $9.50. there are 62 coins in all. find how many of each there are.

 

how many quarters there are

_ quarters

 

how many dimes there are

_ dimes

Answer 1

Hi George,

 

Let Number of Quarters be x, Number of Dimes be y

 

x+y = 62.........eqn 1

25x+10y =950

Divide both sides by 5, we get,

5x+2y =190....... eqn 2

 

now multiply eqn 1 by 5, we get,

 

5x+5y =310, now subtract eqn 2 from this eqn,

-5x -2y =-190

 

3y =120

 

y= 40, 

 x= 62-40=22

 

 

Number of Quarters= 22, Number od Dimes = 40

 

Answer 2

first, assign variables:  Q = the number of quarters, and D = the number of dimes

 

Since there are 62 coins total, we can write the 1st equation:

 

Q + D = 62

 

The next equation is for the dollar value---for example, the dollar value of the quarters is 0.25  times Q

 

So:

0.25Q + 0.1D = 9.5

 

Now you have 2 equations in 2 unknowns, which can be solved