What is the speed of two trains

The ratio between the speeds of two trains is 7:8. If the second train runs 400 km in 4 hours, then the speed of the first train is;

  1. 70 km/h
  2. 75 km/h
  3. 84 km/h
  4. 87.5 km/h
Monis Rasool Professor Asked on 25th October 2015 in Maths.
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1 Answer(s)

Answer: (4) 87.5 km/hr

Explanation:-
The ratio between the speeds of two trains = 7: 8
Then, let the speeds of two trains are 7 X and 8 X

If the second train runs 400 km in 4 hr.
Then, the speed of second train = 400/4
= 100 km/hr

Therefore, 8 X =  100
X = 100/8
X = 12.5 km/hr

Then, the speed of the first train = 7 X = 7 x 12.5
= 87.5 km/hr

Hence, the answer is (4) 87.5 km/hr.

Anurag Mishra Professor Answered on 25th October 2015.
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