19 20n if 1n30 C(n) 15.50n if 30 45 a. Find and interpret C(15) 21 b. How much does it cost to order 45 copies of the book? What about 46 copies? 22. Your answer to 19b should get you thinking. Suppose a bookstore estimates it will sell 45 copies of the book. How many books can, in fact, be ordered for the same price as those 45 copies? (Round your answer to a whole number of books.) 0. An on-line clothing retailer charges shipping costs according to the following formula 55