CAT 2017 Slot 1 — QA Question 4
Basics of TSD/ProportinalityEasy
A man leaves his home and walks at a speed of 12 km per hour, reaching the railway station 10 minutes after the train had departed. If instead he had walked at a speed of 15 km per hour, he would have reached the station 10 minutes before the train's departure. The distance (in km) from his home to the railway station is:
Answer & solution
Answer: 20
Solution
The speed in the second case is 5/4 times the speed in the first case.
Therefore, the time would be 4/5 times the time, i.e., 1/5 less.
This one fifth is 20 min. Therefore, the time taken in the first case is 100 min i.e. 100/60 = 5/3 hours.
The distance = 12 × 5/3 = 20 km.
Hence, 20.