19. Suppose the rate of change of production of a regular worker at a factory is given by Q = 27+24t3t2 dt where p is the is the number of units the worker produces in t hours. Also, after 2 hours, 90 units will have been produced. What is the original production function (with the appropriate value of +C)? (15 pts) Page 5 20. A store nds that its sales revenue changes at a rate given by S '(x) = 3x2 + 300x dollars per day, where x is the number of days after an advertising campaign ends. To determine the long-term effects of the campaign, nd the total sales for the rst week after the campaign ends (use the number of days for the rst week). (12 pts)