Kiran wants to buy blueberries and raspberries to make a fruit tart. Blueberries cost $3.25 per pound and raspberries cost $2.50 per pound. How many pounds of fruit does he buy if he buys 2 pounds of blueberries and 1.5 pounds of raspberries? How many pounds of fruit does he buy if he buys x pounds of blueberries and y pounds of raspberries?