1. A board game contains 75 blackcoins, 21 blue coins, and 43 green coins. How many coins are there in all?   2. Nelson has a small library at home. He has171 books on History, 100 books on Geography, and 161 books on Science. How many books does he have altogether?   3. Mrs.Simon delivered 288 letters in November, 322 letters in August, and 221 letters inJanuary. How many letters did she deliver in the three months?   4. For her new kitchen, Mrs Douglas bought a crockery set, a cutlery set and a pressure cooker. Each item cost $ 72 . How many dollars did she spend?   5. Last month, Jack worked for 183 hours, Greg worked for 147 hours, and Edward worked 39 hours more than Greg. How many hours did they work altogether?