# 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;

- 70 km/h
- 75 km/h
- 84 km/h
- 87.5 km/h

**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.