Like you, I'm about to take the placement exam. It's hard to say whether it's hard or not. It depends on your school and your personal study.

I can tell you a few questions:

1, Party A and Party B are doing running training on the expressway between Party A and Party B. They start from A and B and run to each other at the same time. After everyone finishes the first race, they immediately turn around and run the second race at variable speed. At first, the speed of B is 3/5 of that of A; A's speed in the second run is lower than that in the first run 1/5, and B's speed in the second run is 50% higher than that in the first run. It is known that the second meeting point of A and B is 257 meters away from the first meeting point. Find the distance between a and b. ..

2. Cracks appeared at the bottom of a reservoir, and the pool completely leaked after 40 hours. After the two water inlet pipes A and B are filled with water, open the two water inlet pipes after 30 hours, and fill the pool again after 12 hours. After closing the two water inlet pipes, open the second pipe after 10 hour, and fill the pool again after 6 hours. If all the water is drained now, the bottom of the pool is repaired, and the water inlet pipes A and B are opened respectively, how many hours will it take to fill the pool?

3. A starts from the East Village, and B, C and D start from the West Village. Four people start at the same time and walk towards each other. A, B and D walk at the speed of 3 kilometers, 5 kilometers and 2 kilometers per hour respectively. The place where A and C meet is just the middle point where A and B meet, and A and D meet to find the speed of C.

A production team in the factory produces a batch of parts. Each worker can complete the production task in 9 hours when working in the original post. If the jobs of workers A and B are exchanged and the productivity of other workers remains unchanged, this production task can be completed 1 hour in advance; If the jobs of workers C and D are exchanged, the productivity of other workers will remain unchanged, and it can also be completed 1 hour in advance. If the jobs of A and B, C and D are exchanged at the same time, and the productivity of other workers remains the same, can you finish this production task a few minutes in advance?

There are still a few questions. I'll post them after I finish typing.

Note: They are all difficult problems. Simply read math books.

In addition: all the questions are typed by myself, so I have to work hard without credit!