Answer:
15 quarters
Step-by-step explanation:
Assuming q = quarters and d = dimes...
First, set up the equations. q + d = 28 since we have 28 coins, and the latter is because a quarter is worth $0.25 and a dime is worth $0.1 - totaling $5.05.
q + d = 28
.25q + .10d = 5.05
Try to get one of the variables equal to the equation above. In this case, I tried to get the "q" variables equal to each other.
q + d = 28
4(.25q + .10d) = 4(5.05)
After this, you "subtract" the two equations from each other. Remember that d = 1d, and 1 - .4 = .6
q + d = 28
q + .4d = 20.20
Divide both sides by .6 to get d by itself.
.6d = 7.8
There are 13 dimes.
d = 13
Subtract 13 from the total coins (28) to get the amount of quarters.
28 - 13 = 15
13 dimes, 15 quarters. Hope this helped!
