The price of mailing small packages is $0.32 for the first ounce and $0.21 for each additional ounce. sandra paid $1.16 to mail her package. how much did it weight

The answer is 5 ounces. We can tell this by subtracting 0.32 from 1.16 and then dividing the product (0.84) by 0.21. This should give you 4, but then you have to remember that you subtracted the first ounce that costs 0.32, so when you add it back, you should have an answer of 5 ounces.