choose between tuck or train mode of transportation

An appliance manufacturer has a plant near Toronto that receives small electric motors from a manufacturer located in Winnipeg. The demand for motors is 131,000 units per year. The cost of each motor is $135. The motors are purchased in lots of 4,000 units. The ownership of motors transfers to the appliance manufacturer in Winnipeg. The question is which mode of transportation, truck or train, the appliance manufacturer should use to bring the motors from Winnipeg to Toronto. The railroad company charges $2 per motor, and it takes approximately seven days by train. The trucking company charges $3 per motor, but it takes only three days. The appliance manufacturer will keep 1,000 units as safety stock if a truck is used and 4,500 units as safety stock if a train is used for transportation. Assume 365 days per year. If the holding cost rate is 20 percent of unit cost per year, which mode of transportation will minimize total transportation and in-transit and safety holding cost? Hint. The value of a motor in Toronto for calculating the safety stock holding cost is $135 plus cost of freight per unit. Mode of transportation