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