A chemical manufacturer wants to lease a fleet of 26 railroad tank cars with a combined carrying capacity of 560,000 gallons. Tank cars with three different carrying capacities are available: 7,000 gallons, 14,000 gallons, and 28,000 gallons. Letting t = number of 28,000 railroad tank cars in the fleet, 2-28 7,000-gallon railroad tank cars, and - 3t+54 14,000 gallon railroad tank cars will be in the fleet for a certain range of t. The cost of leasing a 7.000-gallon tank car is $350 per month, a 14,000-gallon tank car is $850 per month, and a 28,000-gallon tank car is $1150 per month. Which of the solutions to the number of each type of tank car in the fleet would minimize the monthly leasing cost? 7,000-gallon tank cars, 14,000-gallon tank cars, and (Simplify your answers. Type whole numbers.) 28,000-gallon tank cars