Suppose the daily benefit you get from spending another hour studying microeconomics is described by B(t) = 12t - tr^2. a) What amount of studying time per day maximizes your benefits? b) Derive the marginal benefits, MB(t) c) Suppose that an alternative use of your time is to play video games that yields a constant benefit of 4 per hour, no matter how many hours you spend playing. How much time should you spend studying microeconomics?