My sister's walking speed is 75m/min, and my sister's walking speed is 45m/min. Twenty minutes after my sister set out, she set out to chase her. Q: How many minutes will it take to catch up?

Xiao Zhang and Xiao Wang walked from A and B respectively. 1 hour 30 minutes later, Xiao Zhang walked more than half of the distance between A and B, when he met Xiao Wang. Xiao Wang's speed is 3.7 km/h, so what is Xiao Zhang's speed?

3. Two cars, A and B, started from the same place and chased a cyclist in front along the same highway. It took the two cars 10 minutes and 6 minutes to catch up with the cyclist respectively. It is known that the speed of car A is 24 km/h and that of car B is 30 km/h. How many kilometers are they apart when they leave?

4. An army marched in a team of 1.2km. At the end of the team, Zhang Ming wanted to contact the battalion commander in front. He caught up with the battalion commander in six minutes. In order to get back to the end of the line, I waited 18 minutes where I caught up with the battalion commander. If he runs from the front to the finish line, how long will it take?

5. Two cars, A and B, leave from two places at the same time. The express train will arrive at B in 8 hours, and the local train 10 hour will arrive at A. ..

(1) When they met, Car B traveled 360 kilometers. Find the distance between the two places.

(2) When they met, B was still 360 kilometers away from the destination. Find the distance between the two places.

(3) When they met, B walked 360 kilometers more than A. Find the distance between the two places.

(4) The two cars meet at a distance of 360 kilometers from the midpoint and find the distance between the two places.

(5) Five minutes later, the two cars are 360 kilometers apart. Find the distance between the two places.

6. My home is 4.8 kilometers away from the library, and my brother walks from home to the library at a speed of 60 meters/minute. 15 minutes later, my brother started from home and rode to catch up with him. The speed of the bicycle was 240 meters per minute. Q:

(1) How far away from home did the elder brother catch up with the younger brother?

(2) The elder brother went to the library soon after catching up with his younger brother and turned back immediately. Soon he met his younger brother, so how many kilometers is the meeting place from the library?

Circular runway problem

1. Xiao Zhang and Xiao Wang each run at a certain speed on the runway with a circumference of 500 meters. Xiao Wang runs180m per minute.

(1) Xiao Zhang and Xiao Wang start from the same place and go in opposite directions at the same time. After 75 seconds, they met and asked Xiao Zhang's speed?

Xiao Zhang and Xiao Wang started from the same place and ran in the same direction at the same time. How many minutes did they meet for the first time?

On the 2.600-meter circular runway, brother and sister run counterclockwise from the same starting point at the same time and meet once every 12 minutes;

If two people run in opposite directions, they meet every 4 minutes. How many minutes does it take for two people to run a lap?

On the 300-meter-long circular runway, Party A and Party B start side by side in the same direction at the same time, with an average of 5 meters per second and 4.4 meters per second. How many meters before the starting line did they meet for the first time after starting?

4. Party A and Party B run around the lake. The circumference around the lake is 400 meters, and Party B runs 80 meters per minute. The speed of Party A is 65438+ 0.25 times that of Party A..

(1) Now two people are running forward at the same time, and B is in front of A 100 meters. How many minutes after they first met?

Now they are running forward at the same time. A is 0/00 meter ahead of B/KLOC. How many minutes after they first met?

Meet and ask 1. Two cars, A and B, left from two places 600 kilometers apart. Car A travels 45 kilometers per hour, while car B travels 40 kilometers per hour. The A train leaves two hours before the B train leaves. How many hours will the B car meet the A car?

2. A train leaves from Station A at 4:30 p.m. at a speed of120km/h.. 1 hour later, another train leaves from bilibili at the same speed, and the two trains meet at 9:30 pm. How many kilometers is the railway between Station A and bilibili?

The express train and the local train leave from A and B at the same time. It is known that the express train is 60 kilometers per hour and the local train is 52 kilometers per hour. A few hours later, the express train met the local train at the midpoint of 32 kilometers. What is the distance between a and b?

4. Two cars, A and B, drive in opposite directions from A and B at the same time. Car A travels 40 kilometers per hour and car B travels 35 kilometers per hour. The two cars meet at a distance of15km. How many kilometers is it between A and B?

5. The distance between Party A and Party B is 640 kilometers, and two cars are driving from Party A to Party B at the same time. The first car travels 46 kilometers per hour, and the second car travels 34 kilometers per hour. The first car arrived at Party B and returned immediately. How many hours did it take for the two cars to drive out and meet?

6. My brother and sister go to a school 540 meters away from A at the same time. My brother walks 60 meters per minute, and my sister walks 48 meters per minute. When my brother arrived at school, he found that he forgot to bring his pencil. He immediately went home to get it and met his sister on the way. How many minutes does it take from the beginning of school to the meeting again?

7. The students of Team A and Team B set out from two places 2700 meters apart at the same time and walked towards each other. A classmate rides a bicycle and shuttles back and forth between the two teams at a speed of 150 per minute. Team A walks 25 meters per minute, while Team B walks 20 meters per minute. How many meters did the cyclist walk when the two teams met?

8.AB and his wife walked to each other at the same time from their home 3000 meters away. A walked 70 meters per minute and B walked 80 meters per minute. A big dog started with him at the same time, walking 100 meters per minute. When the dog meets A, he immediately turns around and runs to A, and then runs to B until AB meets his wife. How many meters did the dog run?

Water velocity problem

The river between A and B is 90 kilometers long. Two passenger ships A and B set sail at the same time. If they meet in opposite directions for 3 hours, Ship A will catch up with Ship B 15 hours in the same direction to find the speed of the ship in still water.

It takes six hours to fuel a ship. Downstream, the speed is15km/h. When I came back, it was countercurrent, and the speed was 12 km per hour. How many kilometers does this ship need to return?