Calvin has $8.80 in pennies and nickels. If there are twice as many nickels as pennies, how many pennies does Calvin have? How many nickels?

Question

I know that I have to make 2 systems of equations. I know ow to solve them I just don't know how to set them up.

Answer 1

Let's set up the variables as nickel=n and penny=p, for how many coins he has of each type. What we know is that Calvin had $8.80 total and that he has twice as many nickels as pennies. So, one equation for his total money and another for how many separate coins: 8.80 = 0.01p + 0.05n 2p=n