Jagan went to another town covering 240 km by car moving at 60 kmph Then he covered 400km by train m......

Jagan went to another town covering 240 km by car moving at 60 kmph. Then he covered 400km by train moving at 100 kmph and then rest 200 km he covered by a bus moving at 50 kmph. The average speed during the whole journey was ?

By car 240 km at 60 kmph
Time taken = 240/60 = 4 hr.
By train 240 km at 60 kmph
Time taken = 400/100 = 4 hr.
By bus 240 km at 60 kmph
Time taken = 200/50 = 4 hr.
So total time = 4 + 4 + 4 = 12 hr. 
and total speed = 240+400+200 = 840 km
Average speed of the whole journey = 840/12 = 70 kmph.

By: MIRZA SADDAM HUSSAIN