Correct Answer - Option 3 : 15 hrs
Given:
Speed of Karnataka Express = 80 km/h
Speed of Rajdhani express = 120 km/h
Distance between Delhi to Bangalore = 3,000 km
Concept used:
When two objects move in the opposite direction, then
Relative speed = S1 + S2
where S1 and S2 = Speed of trains
Formula used:
Speed = Distance/Time
Calculation:
According to the questions,
The relative speed of both trains in opposite directions = 80 + 120
⇒ 200 km/h
Time required to meet the train = Distance/Speed
⇒ 3000/200
⇒ 15 hours
∴ The required time is 15 hours.