Grain is transported from a farm to local grocery stores in either large bags or tiny bags. Large bags can hold 25 kg of grain and requires 4 units of energy to transport. Tiny bags can hold 6 kg of grain and requires 1.5 units of energy to transport. The distribution process has access to 110 units of energy. Because of popularity of buying in bulk, there must be twice as many large bags as tiny bags of rice. Additionally, there must be at least 20 tiny bags of rice. How many of each size of rice bags should be used to maximize the total amount of grain in weight?