A deli sells two types of sandwiches, tuna salad and BLT. The profit on the sandwiches is $1.50 for tuna and $2.50 for the BLT. The amount of bread available is enough for 30 sandwiches. The deli has 4 hours available to prepare sandwiches in the morning. If tuna sandwiches take 6 minutes to prepare, and BLT sandwiches take 9 minutes, how many of each type of sandwich should be prepared to maximize the profit