An elephant in the park eats 350 kilograms of food a day, and the keeper has prepared 5 tons of food, which is enough for the elephant to eat for 20 days?

3. The school should add two new books to the library, one is an encyclopedia for children, each set is 125 yuan, and the other is a mathematical conjecture, each set is 18 yuan, each set is 3 sets, and how much is it?

4. Each set of large sportswear 145 yuan, each set of small sportswear 128 yuan, 34 sets of large sportswear and 25 sets of small sportswear.

(1) How much are two kinds of sportswear?

(2) How much does a * * * cost?

5. The school needs to add 44 sets of desks and chairs, each desk 128 yuan and each chair 17 yuan. How much will it cost?

6. Every tree seedling 16 yuan, buy 3 trees and get 1 tree. How much cheaper is it to buy three at a time?

7. Shopping centers hold promotional activities. 20 yuan bought four bags of washing powder for each bag, and mom bought four bags. How much is each bag cheaper?

8. Jianlibao costs 2 yuan 40 cents per bottle. Buy three bottles and get one free. Buy three bottles at a time. How much cheaper is each bottle?

9. It took a car five hours to walk from A to B at a speed of 64 km/h and only four hours to come back. What is the speed of the car when it returns?

10. Xiaohong's family went to travel by car. The speed of the car is about 65 kilometers per hour. It took six hours on the first day and seven hours on the second day. How many kilometers have you walked in two days?