$A$ train running at a speed of $60\, km/h$ crosses a platform double its length in $32.4\, seconds.$ What is the length of the platform? (in $m$)

With a uniform speed,a car covers a certain distance in $8 \, hours$. Had the speed been increased by $4 \, km/hr$,the same distance could have been covered in $7.5 \, hours$. What is the distance covered? (in $km$)

Heena and Renu are competing in a $100\, m$ race. Initially,Heena runs at twice the speed of Renu for the first $50\, m$. After the $50\, m$ mark,Heena runs at $\frac{1}{4}$ of her initial speed,while Renu continues to run at her original speed. If Renu catches up with Heena at a distance of $N$ meters from the finish line,then $N$ is equal to (in meters).

The speed of a train going from Nagpur to Allahabad is $100 \text{ km/h}$,while its speed is $150 \text{ km/h}$ when coming back from Allahabad to Nagpur. What is the average speed during the whole journey in $\text{km/h}$?

$A$ thief is stopped by a policeman from a distance of $150\, m$. When the policeman starts the chase,the thief also starts running. Assuming the speed of the thief as $7\, km/h$ and that of the policeman as $9\, km/h$,how far would the thief have run before he is overtaken by the policeman? (in $m$)

$A$ train,$240 \, m$ long,crosses a man walking along the line in the opposite direction at the rate of $3 \, km/h$ in $10 \, seconds$. The speed of the train is (in $km/h$):