Question

A train travels from Kolkata to Madhupur with an average speed of 45km/hr . It returs to Kolkata with an average speed of 36km/hr . Find the average speed of the train for upward and downward journey.

Answer 1

Answer:

average speed of the train for upward and downward journey is (45+36)/2

= 40.1 km/hr.

for more information, refer to the attachment.

Step-by-step explanation:

hope it helps ✔✔

Answer 2

Answer:

Average speed of the train for upward and downward journey = 40 km /hr

Step-by-step explanation:

let the distance between kolkata and Madhupur be ' x '

given:

train travels from Kolkata to Madhupur with an average speed of 45 km/hr.

again the train returns to Kolkata with an average speed of 36 km/hr.

so, total distance travelled by the train is ' 2 x '

time taken by the train to reach madhupur = $\frac{x}{45}$    ( time = distance / speed)

time taken by the train to reach kolkata = $\frac{x}{36}$

total time = $\frac{x}{45} +\frac{x}{36}$

               = $\frac{4x + 5x}{180}$

               = $\frac{9x}{180}$

              = $\frac{x}{20}$

okay now let's calculate the average speed of the train for upward and downward journey.

average speed = total distance / total time

                         = $2x * \frac{20}{x}$

                         = 40 km/hr

thus you got the answer ! lucky !

Hope it helps !