A person travels from Delhi to Mumbai in the express train whose speed is 70 km/hr. Another person travels from Mumbai to Delhi in the Rajdhani train whose speed is 90 km/hr. Both persons start their journey at the same time. They meet at Bhopal junction railway station which is 200 km more away from Mumbai than Delhi. Find the distance between Delhi and Mumbai.?

Option 4 : 1600 km

Given:

Speed of the express train = 70 km/hr

Speed of the Rajdhani train = 90 km/hr

Concept:

In these types of questions, we find the time when they meet with the help of relative speed concept and then we find the distance between Delhi and Mumbai.

Formula:

Relative speed = S₁ + S₂ (when trains move in the opposite direction)

Relative speed = S₁ – S₂ (when trains move in the same direction)

Distance = speed × time

Calculation:

let the time when they meet be x hrs

According to the question,

The faster train travels 200 km more than slower train

⇒ 200 = (90 – 70) × x

⇒ x = 200/20 = 10 hrs

Distance travelled by trains in 10 hrs = (90 + 70) × 10

= 1600 km

∴ Distance between Delhi and Mumbai = 1600 km