Question

A bus travels at a speed of 40 km/h for 30 minutes and then, at a speed of 60 [3]
km/h for the next 40 minutes. Calculate the average speed (in km/h) for the
entire journey.solve if

Answer 1

Answer:

36/7

Explanation:

1st case s =40km/h ,t = 30min, d = S x t = 1200km, 2nd case s =60km/h , t= 40 min d=s x t = 60 x 40 = 2400 km , average speed =total distance /totaltime= 2400+1200/40+30=36/7km/h

Answer 2

Answer:

distance covered for first 30 minutes = 40×30/60

= 20 km

distance covered for next 40 minutes = 40×60/60

= 40 km

Average speed =distance/time

= (40+20)/ (30+40)

=60/70

=60/ 1hr 10 min

=51.4 km /hr

Ans: the average speed is 51.4 km /hr