Question

A trains runs for 3 hours at speed of 65 km/hour and for next 2 hours at speed of 70 km/hour. Find the average speed of train for 5 hours journey.
(Hint : Average speed = Total distance/Total Time)

Answer 1

AS IT IS WRITTEN AVERAGE SPEED= TOTAL DISTANCE/TOTAL TIME. SO THE ANSWER IS 67 km/h

Answer 2

first case.. time = 3 hours

and speed = 65km/h

so total speed = 65×3= 195km

in second case..

time = 2 hours

and speed = 70 km/ hours

so total speed = 2×70= 140 km

now average speed = total distance/ total time

140+195/3+2= 335/5= 67

67km/ h.

hope it help you