Answer:
Step-by-step explanation:
If all were dimes, you'd have $3.00. You have $0.40 less. Each dime that is replaced by a nickel subtracts $0.05, so there are $0.40/$0.05 = 8 nickels. That leaves 30-8 = 22 dimes.
You have 22 dimes and 8 nickels in your wallet.
