Question

I have a total of 29 coins-they are quarters and dimes. Together they amount to $5.60. How many quarters do I have? How many dimes?
PLEASE SHOW WORK!!!

Answer 1

450/25= 18

where 450 is $4.50 and 25 is one quarter. there will be 18 quarters. 

560-450=110

110/10=11

where 110 is $1.10 and 10 is one dime. there will be 11 dimes. 

11+18= 29

where 11 is total number of dimes and 18 is total number of quarters. and 29 is total number of coins

Answer 2

When working problems of this sort, it is usually convenient to let the variable represent the highest-value contributor. Here, we choose to let q represent the number of quarters. Then the number of dimes is (29 -q) and the total value is
  25q +10(29 -q) = 560 . . . . . . . . . . value in cents
  15q = 560 -290
  q = 270/15 = 18
As we said, the number of dimes is 29 -q = 11.

I have 18 quarters and 11 dimes.