2. The yacht sailed from A to B for 4 hours, but it was 10km short. It takes 5 hours to sail against the current from B to A, and the ratio of sailing speed to current speed is 9: 1. Find the voyage between a and B.
3. Party A and Party B ride bicycles from A and B, which are 30 kilometers apart. The riding speed of Party A is 10km/ h, and the riding speed of Party B is 8 8km/ h. ..
(1) Car A walks for 25 minutes first, and two people walk in opposite directions. How many hours does car B meet?
② If B leaves early 1 hour, ask: How many hours after A leaves, will B meet him?
(3) If A leaves at 8: 30 a.m. and B leaves at 9: 00 by bike, when will A and B meet?
Both Party A and Party B are running at a constant speed on the 400-meter-long circular runway. They all started in the same place and walked in the same direction at the same time. Party A's network speed 100 m/min, and Party B's network speed is three times that of Party A. How long did it take to meet for the first time? What about the second meeting?
The distance between AB and ab is 33 kilometers. A travels from A to B at the speed of 18km/h, stops at B for 0.5h, and then continues on. At the same time that A starts from A, B travels from B to A at a speed of 24km/h, stops at A 1h, and then catches up with A along the original road. How far is it before B catches up with A?
6. Father and son run around the playground in reverse. When they met in the first lap, the father ran more than 56 meters in the third lap and the son ran less than 14 meters in the half lap. How many meters did the father and son run this time?
7. It takes 30 seconds for a train traveling at a constant speed to enter a 600-meter-long tunnel and leave completely. It is also known that the light beam emitted by the fixed lamp at the top of the tunnel shines vertically on the train for 5 seconds, and the length of the train is obtained.
8. Xiaoming walks from school to Xinhua Bookstore at a speed of 10km/h for 2.2 hours. It took Xiao Qiang 24 minutes to catch up with Xiaoming by motorcycle from school, seeking the speed of motorcycle.
Xiaoying and Xiaoli walk the same distance from school to the shopping mall. Xiaoying walks 5 kilometers per hour and Xiaoli walks 3 kilometers per hour. If Xiaoying leaves 1 hour later than Xiaoli, then she arrives 12 minutes earlier. How far is the school from the shopping center?
10, an army marched, 7.5 hours on foot, 4.5 hours on horseback, * * * on foot 150 km. If riding is 20 kilometers per hour more than walking, how many kilometers did the army ride on foot?
1 1. The car runs between A and B. It is known that the speed from A to B is 40 km/h. If the average speed of the round trip is 48 km/h, find the speed from B to A. ..
12 at 8 o'clock in the morning, two students, Zhang and Li, started from A and B at the same time and walked in opposite directions. It is understood that Zhang is 2 kilometers faster than the hourly rate, 36 kilometers away from them at 10 in the morning and 36 kilometers away from them at 12 at noon. Try to find the distance between a and b.
13. A fan association organized 36 fans to rent a car to watch the football match. There are two kinds of cars that can be rented: one can take 8 people each and the other can take 4 people each. It is required to rent a car without leaving space and overloading.
(1) Please give different car rental schemes (at least three);
(2) If 8 people rent a car in 300 yuan/day and 4 people rent a car in 200 yuan/day, please design the scheme with the lowest cost and explain the reasons.
14, it is known that A runs 5 steps and B runs 6 steps; B ran four steps, and A ran seven steps. Now A runs 55 meters first, and B starts chasing A ... How many meters can A B catch up with A?
15, a seventh-grade student accidentally knocked over the ink while doing his homework, so that only the following words were seen in an homework question: "The distance between A and B is 40 kilometers, the speed of motorcycle is 45 kilometers, and the speed of truck is 35 kilometers." ) "(brackets indicate text partially covered with ink) Please complete this operation and list the equations.