A firm makes mountain bikes and road bikes. Mountain bikes sell for $350, and road bikes sell for $250. At least 200 of each should be made every day. Mountain bikes need 3 labor hours in the fabrication center, and 2 labor hours in the assembly; road bikes need 2 labor hours in the fabrication center and 2 labor hours in the assembly. Each bike also needs half an hour at the testing center. Each day, labor hours available at the fabrication center, assembly, and testing center, are 4000, 3000 and 1000 respectively. Assuming that all bikes made can be sold, how many of each should be made each day to maximize the revenue. Show the problem formation clearly, and write the solution. Solver may be used.