The R.C. Helliot Advertising Company finds that its profits on day t of an advertising campaign is given by P(t) = - 1.5t' + 75t + 47, 000 where P(t) is profit in dollars for day t of the campaign. A) Find a simplified expression for the marginal profit function. (Be sure to use the proper variable in your answer.) MP(t) = B) What is the exact rate of change of profits when 10 days have been passed in the campaign? The rate of change is dollars per day. (Your answer may be negative.) (C) What are their total profits on day 10 of the campaign? Total profits on day 10 are