Average speed for entire distance = (total distance traveled)/(total time)Imsukhi wrote:12. A man travels 600 km by train at 80 km/hr, 800 km by ship at 40 km/hr, 500 km by aeroplane at 400 km/hr and 100 km by car at 50 km/hr. What is the average speed for the entire distance? (a) 60 km/hr (b) 60 5/123 km/hr (c) 62 km/hr (65) 5/123 km/hr
Total distance traveled = 600 + 800 + 500 + 100 = 2000 km
Total time
Here, we need to find the travel time for each leg of the trip.
Time = distance/speed.
So, total time = 600/80 + 800/40 + 500/400 + 100/50
Get common denominator: = 3000/400 + 8000/400 + 500/400 + 800/400
Combine: = 12300/400
Simplify: 123/4 hours
Average speed for entire distance = (total distance traveled)/(total time)
= 2000/(123/4)
= (2000)(4/123)
= 8000/123
= [spoiler]65 5/123[/spoiler]
Cheers,
Brent
