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Xiao Zhang and his father take the bus to the railway station. After 1 / 3 of the bus, it is estimated that if they continue to take the bus, they will arrive at the railway station 30 minutes after the train, and then get off and change for a taxi As a result, the bus arrived at the railway station 15 minutes before the train started. It is known that the average speed of the bus is 40 kilometers per hour. How far is it from Xiaozhang to the railway station?
30 minutes = 0.5 hours
40 * 0.5 = 20 km / h (this is the km / h that takes 30 minutes to get to the railway station by bus)
From the proposition that they have walked 1 / 3, so Xiaozhang to the railway station a total of 60 km
Xiao Zhang and his father are scheduled to take the bus at home to the railway station to visit his grandfather in his hometown. Half the way, Xiao Zhang asks the driver when he arrives at the railway station. The driver estimates that the train will just leave when he continues to take the bus to the railway station. According to the driver's advice, Xiao Zhang and his father immediately get off the bus and take a taxi. The speed is doubled, so they catch the fire The bus arrives at the railway station 15 minutes before departure. It is known that the average speed of the bus is 30 km / h. how far is it from Xiaozhang to the railway station?
According to the time difference, we can set up a linear equation of one variable: 160x-1120 x = 14, that is: 1120 x = 14, the solution is: x = 30 km
Xiao Ming's home is 2km away from the railway station. His father walked to the railway station for a business trip in Beijing for just 15 minutes. Xiao Ming found that his father forgot to bring his ID card and rushed to chase him by bike. It is known that his father walks 90 meters per minute and Xiao Ming rides 240 meters per minute. How long does it take him to catch up with his father?
Please judge whether the practical problems compiled by the student are in line with the reality. If not, please help him to revise them?
After time t catch up, then
90*15+90*T=240*T
T = 9 minutes
90 * (15 + 9) = 2130m
Because Xiaoming's house is 2 kilometers away from the railway station, so my father has arrived at the station first
Xiaoming's time to the station is 2000 / 240 = 25 / 3 (minutes)
That is, Xiaoming can catch up with his father after 25 / 3 (minutes)/
In addition, if it's a junior high school problem, it's no problem. If it's a primary school problem, it can improve Xiaoming's cycling speed
If the speed of Xiaoming is V, dad and Xiaoming arrive at the station at the same time; then
V（2000/90-15）=2000
V=3600/13=276.92
Therefore, Xiaoming's speed must be greater than 276.92 M / min to ensure that Dad can catch up with dad before he arrives at the station
RELATED INFORMATIONS
- 1. Xiao Ming's father drove from home to the railway station at the speed of 50 km / h, 15 minutes earlier than the train. If he drove at the speed of 40 km / h, he was 15 minutes later than the train. How fast did he arrive 10 minutes earlier than the train?
- 2. English translation In our school,the most popular____ of____ to school is by bike.
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- 11. Xiao Zhang and his father are scheduled to take the bus at home to the railway station to visit his grandfather in his hometown. Half the way, Xiao Zhang asks the driver when he arrives at the railway station. The driver estimates that the train will just leave when he continues to take the bus to the railway station. According to the driver's advice, Xiao Zhang and his father immediately get off the bus and take a taxi. The speed is doubled, so they catch the fire The bus arrives at the railway station 15 minutes before departure. It is known that the average speed of the bus is 30 km / h. how far is it from Xiaozhang to the railway station?
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