1. There are 2 cakes. Each cake is cut into 10 parts. Each part is further cut into 2 pieces. How many cake pieces are there in all?   2. There are 4 balloons in a bag. There are 4 bags in one box. How many balloons are there in 3 boxes?   3. Everyday Brian exercises 3 minutes in the morning and 6 minutes in the evening. How many minutes does he exercise in 4 days?   4. A school has 3 dining halls. Each dining hall has8 tables. If there are four children to each table, how many children stay for lunch?   5. There are 2 paintings on each of three walls of a room. If an art gallery has 8 such rooms, how many paintings are there in its collection?