Question

A train takes 4 h to travel from station A to station B and return to station B in 6 h.
distance between station A and station B is 800 km. Find the average speed of the train.

Answer 1

GIVEN :-

★ Distance between station A and B = 800km

★ Time taken to go from Station A to B= 4 hours

★ Returns back From B to A = 6 hours

TO FIND :-

★Average speed of train

We know that

$\boxed{\sf \ Average \ speed = \dfrac{Total \ Distance}{Total \ time }}$

Total distance = Distance of A to B + B to A

●Total distance = 800+800

$\longrightarrow\sf Average \ speed = \dfrac{d_1+d_2}{t_1+t_2}\\ \\ \longrightarrow\sf Av.\ speed = \dfrac{800+800}{6+4}\\ \\ \longrightarrow\sf \ Av.\ speed = \dfrac{1600}{10}\\ \\ \longrightarrow\sf \ Av.\ speed = 160km/h$

$\boxed{\sf{\dag\ \ Average \ speed\ of \ Train = 160km/h}}$

Answer 2

Explanation :

Here time taken to travel from station A to B is 4 hours.

Time taken to travel from station B to A is 6 hours.

Distance b/w station A & B is 800 km.

What is average speed of train?

As the train travels from station A to B & comes back to A, that means the train travels the same distance twice.

⇒ Total distance = AB + BA

⇒ Total distance = 800 + 800

⇒ Total distance = 1600 km.

Now,

⇒ Total time = ABₜᵢₘₑ + BAₜᵢₘₑ

⇒ Total time = 4 + 6

⇒ Total time = 10 h

Again using formula now :-

Average speed = Total distance/Total time

⇒ Av. speed = (1600)/(10)

⇒ Av. speed = 160 km/h

Therefore,

∴ Average speed of train = 160 km/h