Question

A train travels some
distances with a speed of 30 km/hr and return
with a speed of 45 km /hr . calculate the
average speed of the train​

Answer 1

Explanation:

Questions

A train travels some distances with a speed of 30 km /hour and return with a speed of 45km/hour calculate the average speed of train.

Formula

Average speed =

$\frac{sum \: of \: total \: distance \: covered \: by \: train}{sum \: of \: all \: time \: taken \: by \: train}$

Time =

$\frac{distance}{speed}$

Solutions

Given

speed of A train = 30km/hour

Speed of B train = 45km/hour

let the total distance covered by train be x

Time taken by A train = X/30hour

Time taken by B train = X/45hour

According to question

Average speed =

$\frac{(x + x)}{ (\frac{x}{30} + \frac{x}{45} ) } \frac{km}{hour}$

Average speed of train =

$\frac{180x}{5x} \frac{km}{hour}$

Average speed of both train = 36km/hour

Note

• Unit of average speed is km/hour .