a purse contains $3.65 in quarters and dimes. There are 9 more quarters than dimes.

Question

i dont understand the problem and i need help with it. 

Answer 1

Assuming that the questions asks: "How many dimes and how many quarters are in the purse?"

We can first think, "How can we show an equation that has both the number of dimes, the number of quarters, and the value of a dime (.10) and the value of a quarter (.25)?

We therefore create/think of this general equation: Total amount= .10(# of dimes) + .25(# of quarters)

Now, we can make a chart (using the method of trial and error) to find our solution:

# of dimes|# of quarters | Total amount of money

     0         |        9          |       $2.25 because .10(0) + .25(9)= $2.25

     1         |      10          |       $2.60 because 10(1) + .25(10)= $2.60

     2         |      11          |       $2.95 because 10(2) + .25(11)= $2.95

     3         |      12          |        $3.30 because 10(3) + .25(12)= $3.30

     4         |      13          |        $3.65 because 10(4) + .25(13)= $3.65

This table shows us that in order for the purse to contain $3.65 while there are nine more quarters than there are dimes present, the number of quarters must be thirteen and the number of dimes must be four.