A company in the desert can transport goods to rural cities either by camel caravans or desert trucks. A camel caravan can deliver 50 units of goods per trip and takes 12 hours. A desert truck can deliver 150 units of goods per trip and takes 5 hours. However, due to the cost of fuel, the company prefers to have more camel caravans than desert trucks.  If the company needs to deliver 1500 units of goods, how many of each method of transportation should the company organize to minimize the total number of hours required?