Question

Please please please please help me please please please help me please please help me please

Answer 1

Assume the distance AB to be 30 km .

Time to travel AB is 1 h.

Time to travel B to A will be more and = (30/20) h

Total distance 60 km and time is (1+ (30/20))= 50/20.

Average speed is 60/ ( 50/20) = 24 km/h

112 Views · Answer requested by Rajlakshmi Dash



Jagrata Banerjee, Aviation Enthusiast and a Big Fan of Airplanes

Answered Jul 14, 2018 · Author has 558answers and 409k answer views

Thanks for the question, Rajlakshmi Dash.

Since, the time taken to go from A to B differs from that of B to A, we'll calculate the average speed like this.

Let the distance from A to B is D kms. Total distance for the entire journey is 2D kms.

Time taken to go from A to B is D/30 hr and that of B to A is D/20 hr. So, total time taken is—

T = (D/30) + (D/20). By solving, we will get,  T = D/12 hrs.

Average speed = Total distance/Total time.

Av.speed = 2D ÷ D/12

=> 2D * 12/D = 24 km/h.

So, average speed is 24 km/h.

Hope you got your answer. Thank