Question

Two trains are going from Bangalore to Chennai with a speed of 80km/hr and 100km/hr. If the train with slower speed starts 1 hour before then find the time taken by the second train to catch the 1st train.
1. 6 hours
2. 5 hours
3. 4 hours
4. 8 hours

Answer 1

Correct Answer - Option 3 : 4 hours

GIVEN:

Speed of trains are 80 km/hr and 100 km/hr and lower speed train start 1 hour earlier

FORMULA USED:

Distance = Time × Speed

CALCULATION:

Speed of trains are 80 km/hr and 100 km/hr and slower speed train start 1 hour earlier

Distance covered by slower train in 1 hour = 80 × 1 = 80 km

Relative speed = 100 - 80 = 20 km/hr

So the time is taken by the faster train to cross the slower train = 80/20 = 4 hours

∴  Time taken by 2nd train to catch the 1st train is 4 hours