How many dimes do you have if you have 80 nickels

You would have 40 dimes ...

Dimes are worth twice as much as a nickel, therefore you would divide the amount of nickels by half:

80 / 2 = 40

Therefore you have 40 dimes.

Another way to do this is to find your current amount of money, since dimes are worth 10 cents and nickels are worth 5 cents:

80 * 5 = 400 cents

400 / 10 = 40 dimes