Question

Gautam covers certain distance with different speed. He travels at the rate of 3 km/h for 5 hours and again at the rate of 9 km/h for 5 hours. Then, find his average speed.
1. 5 km/h
2. 3 km/h
3. 6 km/h
4. 7 km/h

Answer 1

Correct Answer - Option 3 : 6 km/h

Given:

Two speed are 3 km/h and 9 km/h

Formula used:

If time₁ = time₂, and two different speed are given, then formula for calculation average speed is as follows:

Average speed = Sum of speed/Number of different speed:

Calculation:

Average speed = (3 + 9)/2

⇒ 6 km/h

Alternative method

Total distance = (3 × 5) + (9 × 5) = 60 km

Total time = (5 + 5) hours = 10 hours

Average speed = 60/10 = 6 km/h