A boy while driving to his school covers at the average speed of 15km/h.On his return trip along the same route, covers at the average speed of 25km/h due to less traffic.What is the average speed for the whole trip
V = (V1+V2)/2 = (15+25)/2 = 20 km/h.
To find the average speed for the whole trip, we need to calculate the total distance traveled and divide it by the total time taken.
Let's assume the distance between the boy's school and his home is "D" kilometers.
Now, we can calculate the time taken for the outbound trip:
Time taken = Distance / Speed
So, time taken for the outbound trip = D / 15.
Similarly, the time taken for the return trip would be:
Time taken = Distance / Speed
So, time taken for the return trip = D / 25.
The total time taken for the whole trip would be the sum of the outbound and return trip times:
Total time taken = (D / 15) + (D / 25)
To find the average speed, we need the total distance and the total time:
Total distance = 2D (since he covered the same distance twice)
Average speed = Total distance / Total time taken
Average speed = 2D / ((D / 15) + (D / 25))
To simplify the equation, we need to find a common denominator for the two fractions in the denominator:
Average speed = 2D / ((25D + 15D) / (15 * 25))
Average speed = 2D / (40D / 375)
Average speed = (2D * 375) / 40D
Average speed = 750D / 40D
Average speed = 18.75 km/h
Therefore, the average speed for the whole trip is 18.75 km/h.