An aeroplane travels 2500 km, 1200 km and 500 km at the rate of 500 km/hr, 400 km/hr and 250 km/hr respectively. Find its average speed for the whole journey.

Asked by Topperlearning User | 19th Sep, 2016, 02:37: PM

Expert Answer:

Distance space equals space 500 space km
Speed space equals space 500 space km divided by hr
Time space taken space to space cover space 2500 space km space equals space 2500 over 500 equals space 5 hr
Distance space equals space 1200 space km
Time space equals space 400 space km divided by hr
Time space taken space equals 1200 over 400 equals 3 hr

Distance space equals space 500 space km
Speed space equals space 250 space km divided by hr

Time space taken space equals space 500 over 250 equals 2 space hrs

Total space distance equals space 2500 plus 1200 plus 500 equals 4200 space km
Total space time space taken space equals space 5 space plus space 3 space plus space 2 space equals space 10 space hr
Average space speed space equals space 4200 over 10 equals 420 space km divided by hr

Answered by  | 19th Sep, 2016, 04:37: PM