RRB NTPC · Question 43
Two cycles start from a house with a speed of 24 km/hr. at interval of 15 minutes. With how much more sped (km./hr) the woman coming from the opposite direction towards the house has to travel to meet the cycles at an interval of 10 minutes? A. 13 B. 11 C. 12 D. 14
Show answer & explanation
Answer: (A) C
Explanation
The two cyclists are 24 × 15/60 = 6 km apart. The woman meets them 10 minutes apart, so she and a cyclist close that 6 km gap in 1/6 hour: relative speed 36 km/h. Her speed = 36 − 24 = 12 km/h.