1. A board game contains 28 white coins, 25 yellow coins, and 15 black coins. How many coins are there in all?   2. Mr. Hick borrowed from the library 15 books on Thursday, 11 books on Friday, and 31 books on Saturday. How many books did he borrow altogether?   3. Mrs. Martin delivered 21 letters in September, 27 letters in February, and 25 letters in October. How many letters did she deliver in the three months?   4. For her new kitchen, Mrs. Martin bought a crockery set, a cutlery set and a pressure cooker. Each item cost $ 23 . How many dollars did she spend?   5. Jack played for 3 hours, Greg played for 9 hours, and Edward played 2 hours more than Greg. How many hours did they play altogether?