Algebra
posted by Aimee .
The floor of the studio is covered with 615 square tiles that measure 2 feet by 2 feet. The owner of the studio replaced the tiles last year. The tiles cost $15 for a set of 8 and $2 for each additional tile.
What is the monthly increase the owner charged each of her 34 students over a 6month period to cover the cost of replacing the tiles?

There are 435 tiles, not 615. Sorry.