Question

Usan Bolt and Tyson Gay two sprinters start running around a circular track of length 400 m from the same point at speeds of 35 km/hr and 25 km/hr. When will they meet for the first time if they are running in opposite directions?
1. 30 seconds
2. 28 seconds
3. 24 seconds
4. 26 seconds

Answer 1

Correct Answer - Option 3 : 24 seconds

Given∶

Track length = 400 m

Speed of Bolt = 35 km/hr

Speed of Gay = 25 km/hr

Formula Used∶

Relative speed in opposite direction = (speed 1+ speed 2)

Time = Distance/Speed

Calculation∶

Distance (track length) = 400 meter

Relative speed = (35 + 25) km/hr = 60 km/hr = 60 × 5/18 m/sec

Hence, Time taken to meet = length of track/relative speed = 400/(60 × 5/18) = 400 × 18/60 × 5 = 24 seconds

∴ They meet for the first time after 24 seconds.