Question

help me.. a car moves for half of its time at 80km/h nd for rest of time at 40km/h.total distance coverd is 60km..wat is averge speed of car?

Answer 1

Let's use ' t ' to represent half of the time, in hours.

The distance traveled in the first half of the time is  (80 t) km.

The distance traveled in the last half of the time is  (40 t) km.

The total distance covered is    (80t + 40t) = (120t)  km.

You said that the total distance covered was  60 km,
so ...
                             120 t  =  60 km

Divide each side by  120 :      t (half of the time) = 0.5 hour

Average speed = (total distance covered) / (time to cover the distance)

                           =      (60 km)  /  (1 hour)

                           =            60 km/hr .