Question

Amar and Ujjwal are running on a hexagonal track of side 9 m. Speed of Amar is 66 m/s and that of Ujjwal is 72 m/s. They start from the same point at the same time in the same direction. When will they meet again for the first time?
1. 9 seconds
2. 6 seconds
3. 18 seconds
4. 12 seconds

Answer 1

Correct Answer - Option 1 : 9 seconds

Given:

Amar and Ujjwal are running on a hexagonal track in the same direction

One side of hexagonal track = 9 m

Speed of Amar = 66 m/s

Speed of Ujjwal = 72 m/s

Formula used:

When two bodies A and B are moving with speed ‘a’ kmph and ‘b’ kmph respectively, then the relative speed of two bodies is

(i) (a + b) kmph if they are moving in opposite direction

(ii) (a - b) kmph if they are moving in same direction

Time taken to meet each other = distance between them / relative speed

Perimeter of hexagon = 6 × side

Calculation:

Relative speed = speed of Ujjwal - speed of Amar = 72 - 66 = 6 m/s

Distance to travel = 6 × 9 = 54 m (as it is a hexagonal track)

Time taken to meet each other = 54/6 = 9 secs

∴ They will meet again after 9 seconds for the first time.