A meal service company delivers meals to customers either on electric bikes or scooters. A bike can hold 8 meals and requires 3 units of charge. A scooter can hold 5 meals and requires 2 units of charge. Since the city is more friendly towards scooters, at most 30% of the electric vehicles can be bikes and at least 20 scooters must be used. If the company only has 200 units of charge available, how many of each vehicle should be used to maximize the number of meals that can be delivered?