Question

Choose the correct answer from the alternatives given.
Two trains for Bhopal leave Delhi at 9 am and 8:30 am and travel at 90 km/hr and 80 km/hr respectively. How many kilometres from Delhi will the two trains be together?

• A. 360 km
• B. 320 km
• C. 270 km
• D. 280 km

Answer 1

The correct option is A 360 km

Distance travelled by the train at 80 km/hr in 30 min. = 40 km. This distance of 40 km is to be covered with a relative speed of
(90 - 80) = 10 km/hr.
Time taken to cover this distance = $\frac{40}{10}$ = 4 hr.
Hence, the trains will be together after 4 $\times$ 90=360 km from Delhi.