The owner of a skating rink rents the rink for parties at $600 if 50 or fewer skaters attend, so that the cost per person is $12 if 50 attend. For each 5 skaters above 50, she reduces the price per skater by $0.50.

(a) Construct a table that gives the revenue generated if 50, 60, and 70 skaters attend.

(b) Does the owner's revenue from the rental of the rink increase or decrease as the number of skaters increases from 50 to 70?

(c) Write the equation that describes the revenue for parties with x more than 50 skaters.

(d) Find the number of skaters that will maximize the revenue?