1. A board game contains 11 green coins, 12 white coins, and 20 yellow coins. How many coins are there in all?   2. Mr. Buffet borrowed from the library 24 books on Friday, 15 books on Tuesday, and 12 books on Thursday. How many books did he borrow altogether?   3. Mrs. Moore delivered 23 letters in August, 26 letters in September, and 22 letters in October. How many letters did she deliver in the three months?   4. For her new kitchen, Mrs. Moore bought a crockery set, a cutlery set and a pressure cooker. Each item cost $ 27 . How many dollars did she spend?   5. Jack played for 2 hours, Greg played for 9 hours, and Edward played 9 hours more than Greg. How many hours did they play altogether?