Emmy is spending her summer helping manage a construction and excavation company. The company needs to purchase a lot of stone to redo gravel driveways for several customers (a common summer project for business and homeowners). She'd like to do everything in crushed stone, but at $65 per ton, it's too expensive. Pea stone is cheaper, and if she buys 80 tons of it, the quarry will give her a special price of $35 per ton. Given the total area of all the driveways, 80 tons of pea gravel will be a good portion of what she needs. To give her clients a good deal, she wants to target an average price of $50 per ton for the stone mixture. She wants to buy the special package of 80 tons of pea gravel and as much crushed stone as possible. If we let t be the number of tons of crushed stone, which equation best represents the situation?