Shishang likes playing badminton with her friends. Her utility function for playing badminton every week is given by U(t) = 11t - 2t2, where t is measured in hours. They play on a badminton court, which they can rent per hour. Suppose the current price to play on the badminton court is $2.50 per hour. a) How many hours should Fang play if she wishes to maximise her utility. b) Explain what we mean by the principle of diminishing marginal utility. Does the principle apply in her case? Explain why