A and B are jogging around a 2 km circular track. They start from the same point and run in opposite directions. A's speed is 8 km/h and B's speed is 12 km/h. At what time will they meet for the tenth time if they start at 7:00 a.m.?
Show answer & explanation
Correct answer: D
Explanation
Given:
Length of circular path = 2 km
Speed of A = 8 km/h
Speed of B = 12 km/h
Both run in opposite directions
By formula:
Relative speed = v₁ + v₂
Time of meeting = Distance / Relative speed
Relative speed = 8 + 12 = 20 km/h
Time of first meeting = 2 / 20 hours = 6 minutes
Time of meeting for the tenth time = 10 × 6 = 60 minutes
Starting time = 7:00 am
7:00 + 60 minutes = 8:00 am