Question

a person travels initially from Delhi with 400 km/h and he takes to over for returning it from Agra to Delhi distance between Agra and Delhi is just 800 km find speed of person in case of retardation.​

Answer 1

Let the each half of the running time be t.

During first half time, speed of car is 80 km/h

Distance covered  d1=80t km

During second half time, speed of car is 40 km/h

Distance covered  d2=40t km

Total distance covered  d=d1+d2=80t+40t=120t

Total time taken   T=2t

Average speed   vavg=Td=2t120t=60 km/hr

Answer 2

Answer:

60 KM/Hr

Explanation:

Let the each half of the running time be t.

During first half time, speed of car is 80 km/h

Distance covered d

1

=80t km

During second half time, speed of car is 40 km/h

Distance covered d

2

=40t km

Total distance covered d=d

1

+d

2

=80t+40t=120t

Total time taken T=2t

Average speed v

avg

=

T

d

=

2t

120t

=60 km/hr

Option C is correct