To mail a package, the ups store charges $0.45 for the first two ounces and $0.12 for each additional ounce. bill paid $3.57 to mail a package. how many ounces did the package weigh?

Last year, laura had $30,000 to invest. she invested some of it in an account that paid 7% simple interest per year, and she invested the rest in an account that paid 8% simple interest per year. after one year, she received a total of $2230 in interest. how much did she invest in each account?