There are 11 books on a shelf. 4 of these books are new. The rest of them are used. What is the ratio of all books on the shelf to used books?

What is the ratio of used books to new books?

Tim's phone service charges $23.06 plus an additional $0.22 for each text message sent per month. if tim's phone bill was $28.56, which equation could be used to find how many text messages, x, tim sent last month?

Me. i can't figure out this question. give an explanation too. .

Money off coupons have been circulated to 300 households. only 2/5 of these were redeemed (used) in the local supermarket to get a free shampoo. what fraction of coupons were unused? (ps: write how you got the answer)