A tourism company can buy sedans or buses to add to their fleet of vehicles to increase their capacity for more tourists. A sedan can seat 50 tourists per day but results in 10 units of pollution. A bus can seat 250 tourists per day but results in 40 units of pollution. The city has limited this tourism company to producing at most 800 units of pollutants per day. To make a profit, this tourism company must take care of at least 4600 customers per day. Planning to make a profit, how many sedans and how many buses should this tourism company purchase to decrease the total number of vehicles needed?