The residents of Amity Island want the city government to renovate the beach. However, there is debate over how much to spend on renovations. Amity Island has 500 residents: 200 who live close to the beach (and will benefit more from the renovations), and 300 who live farther away (and will benefit less). The marginal benefits of the beach renovations for each resident are given by the below equations, where R represents the worker hours needed for renovations. For Each Close Resident: M BC = 55 R For Each Far Resident: M BF = 20 2R (a) If the beach renovations cost $1,000 per hour, what is the socially optimal hours of reno- vations R