Math
posted by Sara .
The school had a bake sale to raise money. A group of 11 students bought either chocolate chip cookis for $.40 cents each or brownies for $.50 cents each. The total amount they spent was $5.10. How many chocolate chip cookies and brownies did they buy?

I will assume that each of the 11 students bought either one cookie or one brownie.
let the number of cookies be c
then the number of brownies is 11c
solve this equation:
40c + 50(11c) = 510
(let me know if you don't get cookies =4
brownies = 7 ?)