Quarters and dimes

Question

The toll collector st the riverview exit notices that she has the same number of dimes as quarters in her box. If there is a total of $9.80 in the box, and she has only dimes and quarters, how many of each coin does she have?

Answer 1

Hi Kylah.

 

We know 2 things. First, there is the same number of quarters as dimes, so...

 

Q = d

 

Also, the value of all the quarters + the value of all the dimes = 980 cents. (Life is easier without decimals), so...

 

25q + 10d = 980.

 

Since q and d are the same, just use the equation above but use the same letter in each spot. So...

 

25q + 10q (instead of d) = 980

 

So 35q = 980, so...

 

Q = 980/35, which equals...

 

:-) your turn!