Answer the next 6 questions using the following marginal benefit (MB) and marginal cost (MC) functions for activity A: MB = 1 200 - 20A and MC 500 + 30A and the following total benefit (TB) and total cost (TC) functions: TB = 1 200A-10A2 and TC = 500A + 15A 1 - Undertaking the 10th unit of the activity A increases Net Benefit by 200 2 - Undertaking the 20th unit of the activity A decreases Net Benefit by 300 3- The optimal level of activity A* is 14 4 - At the optimal activity level of A*, Net Benefit is equal to 5- Eliminating the 25th unit of the activity Total Cost by 6- What level of activity maximizes TOTAL Benefit? Total Benefit by and