Two trains start from Lucknow and Delhi respectively and travel towards each other at a speed of 50 km/hr. and 40 km/hr. respectively. By the time they met the first train had travelled 100 km more than the second. Find the distance between Lucknow and Delhi?
1280 km
680 km
900 km
624 km
Let the train running from Lucknow and Delhi be P and Q respectively,
We know that, formula:
Speed = Distance/Time.
Let they meet after ‘a’ hours,
Then, distance covered by Train ‘P’ = 50a,
And, distance covered by Train ‘Q’ = 40a.
Now, we have
⇒ 50a – 40a = 100
⇒ a = 10 hours.
Since, both these have travelled 10 hours each, Distance travelled by Train P = 50 × 10 = 500 km
Distance travelled by train Q = 40 × 10 = 400kms
Total distance = 500 + 400
= 900 km.
Hence, the required answer is 900 km