CAT 2020 Slot 3 — QA Question 2
Relative SpeedEasy
A and B are two railway stations 90 km apart. A train leaves A at 9:00 am, heading towards B at a speed of 40 km/hr. Another train leaves B at 10:30 am, heading towards A at a speed of 20 km/hr. The trains meet each other at
Answer & solution
- A
11:45 a.m.
11 a.m.
- C
10:45 a.m.
- D
11:20 a.m.
Solution
Train A starts at 9 a.m. whereas Train B starts at 10:30 a.m.
Distance travelled by A till 10:30 a.m. = 40 × 1.5 = 60 kms.
At 10:30 a.m. remaining distance between A and B = 90 – 60 = 30 kms.
Time taken for both of them to meet now = 30/(40 + 20) = 0.5 hours i.e., 30 mins.
∴ Both trains meet half after 10:30 a.m. i.e., at 11 a.m.
Hence, option (b).