Answer:
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Let d be the number of dimes and q be the number of quarters.
We can set up two equations based on the information given:
- d + q = 14 (14 coins in total)
- 0.10d + 0.25q = 2.15 (total value of his change is $2.15)
Use substitution here:
- d = 14 - q (from the first equation)
- 0.10(14 - q) + 0.25q = 2.15 (substituting into the second equation)
- 1.40 - 0.10q + 0.25q = 2.15
- 0.15q = 0.75
- q = 5
So he has 5 quarters.
We can plug that back into either equation to find the number of dimes:
So he has 9 dimes and 5 quarters.