Vikas covered a certain distance by bike. If he covers 40% of the distance at 40 km/h, 50% of the distance at 25 km/h and the remaining 10% distance at 10 km/h. Find his average speed over the whole distance.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 25 km/h.
Formula used:
Average speed = Total distance/total time ----- (1)
Calculations:
Let the total distance be 10x.
Time taken to complete 40% of the distance at 40 km/h speed = 4x/40
Time taken to complete 50% of the distance at 25 km/h speed = 5x/25
Time taken to complete Remaining distance at 10 km/h speed = x/10
Using equation (1), we get
⇒ Average speed = 10x/(4x/40 + 5x/25 + x/10) = 25 km/h