Answer:
We can use the formula:
average speed = total distance / total time
To find the total distance, we add the distances for each event:
total distance = 1.5 km (swimming) + 40 km (cycling) + 1 km (running) = 42.5 km
To find the total time, we add the times for each event:
time for swimming = distance / speed = 1.5 km / 2.5 km/h = 0.6 hours
time for cycling = 40 km / 12 km/h = 3.33 hours
time for running = 1 km / 9 km/h = 0.11 hours
total time = 0.6 hours + 3.33 hours + 0.11 hours = 4.04 hours
Now we can calculate the average speed:
average speed = total distance / total time = 42.5 km / 4.04 hours ≈ 10.52 km/h
Therefore, Farhan's average speed for the entire competition is approximately 10.52 km/h.