Question

A man walks 6 km at 12 km/h and returns at 10 km/h. Find his average speed.​

Answer 1

Given :

• A man walks 6 km at 12 km/h

• And he returns at 10km/h

To Find :

• Average speed

Solution :

★ Total distance covered :

Man walks at a distance = 6km

Total distance = 6 × 2 = 12

Total distance = 12km

★ Time taken on the way :

The man walks at a distance = 6km

Speed = 12km/h

Time = Distance / Speed

Time = 6 / 12

Time = 0.5 hour

★ Time taken on the return :

The man returns at a distance = 6km

Speed = 10 km/h

Time = Distance / Speed

Time = 6 / 10

Time = 0.6 hour

★ Total time taken :

Total time taken = 0.5 + 0.6

Total time taken = 1.1 hour

★ Average speed :

To find average speed, we should divide total distance covered by total time taken.

So, we know that

• Total distance covered = 12
• Total time taken = 1.1

⇒ Average speed = Total distance covered / Total time taken

⇒ Average speed = 12 / 1.1

⇒ Average speed = 10.90 km/h

•°• Hence, The average speed is 10.90 km/h.