1. The infants buyer is buying one-piece sleepers from different vendors to retail at $12. The buy is as follows: - Vendor A: 600 sleepers at a cost of $4.20 each - Vendor B: 480 sleepers at a cost of $5.10 each a) Calculate the markup $ and markup % for Vendor A b) Calculate the markup $ and markup % for Vendor B c) Calculate the cumulative markup % for the total buy.