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the distance between two villages P and Q is x km . A train running between P and Q arrives 3 minutes behind the scheduled time
when it travel at an average speed of 45km/h but arrives 9 minutes ahead of the scheduled time when it travels at an average speed of 60km/h,
(i) calculate distance x
ii) calculate the scheduled time for the journey
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The travel time at the speed of 45 km/h is .
The travel time at the speed of 60 km/h is .
The time at the speed 45 km/h is in 3+9 = 12 minutes longer than at the speed 60 km/h.
It gives you a "time" equation:
= .
To solve it, multiply both sides by 180. You will get
4x - 3x = 36.
x = 36.
Thus you just found the distance. It is 36 kilometers.
The time spent at the speed of 45 km/h was = of an hour = 48 minutes.
It was in 3 minutes longer than the scheduled time.
Hence, the scheduled time is 48-3 = 45 minutes.
All question are answered. The problem is solved.
For similar solved problems see the lesson
- How far do you live from school?
in this site.
Also, you have this free of charge online textbook in ALGEBRA-I in this site
- ALGEBRA-I - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Travel and distance".