A gem factory has two drills, a high intensity one and a low intensity one. Each day, the high intensity drill can process 50 gems and requires 50 units of water to dissipate heat. Each day, the low intensity drill can process 30 gems and requires 20 units of water to dissipate heat. Each day the factory must process 800 gems and they have available 700 units of water. Since the high intensity drill produces a lot of noise pollution, at most 40% of the drills can be high intensity ones. Further, at least 10 should be low intensity drills. How many of each drill should be used to minimize the total number of drills needed?