Margo can purchase tile at a store for $0.89 per tile and rent a tile saw for $49. At another store she can borrow the tile saw for free if she buys tiles there for $1.59 per tile. How many tiles must she buy for the cost to be the same at both stores?

Last month, leonhard euler's watch kiosk at the mall had total sales of $9,489. merchandise totaling $225 was returned. the goods that were sold cost leonhard euler's $5,481. operating expenses for the moth were $992. what was the gross profit on sales?