First, find the values of a quarter and a nickel. These are 25 and 5 cents.
Then, find the difference, it's 20 cents.
Multiply 5 or 25 by 8, and find the difference of that and 80.
Divide that by 20, and that's how much of the other coin you didn't use above to multiply.
Subtract 8 - 2 or 8 - 6 for the coin you did use.
So, 2 quarters, 6 nickels.