1. Adaminvites 21 boys and 29 girls to his birthday party. How many friends did he invite?   2. There are 3 cakes. Each cake is cut into 7 pieces. How many pieces are there in all?   3. There are 18 sandwiches to be arranged equally in 9 trays. How many sandwiches will there be in each tray?   4. Dad has planned 4 games for the party. Each game would have 3 winners. How many prizes would Dad give away?   5. Mom places 14 paper plates on the table in 7 rows. How many paper plates are there in each row?