$A$ train is travelling at a rate of $45 \, km/hr$. How many seconds will it take to cover a distance of $\frac{4}{5} \, km$?

Two trains $M$ and $N$ cross a pole in $25 \text{ seconds}$ and $1 \text{ minute } 15 \text{ seconds}$ respectively. The length of train $M$ is half the length of train $N$. What is the respective ratio between the speed of train $M$ and train $N$?

One aeroplane started $30 \, \text{minutes}$ later than the scheduled time from a place $1500 \, \text{km}$ away from its destination. To reach the destination at the scheduled time,the pilot had to increase the speed by $250 \, \text{km/hr}$. What was the original speed of the aeroplane? (in $\text{km/hr}$)

Walking at $3 \, km/h$,Pintu reaches his school $5 \, minutes$ late. If he walks at $4 \, km/h$,he will be $5 \, minutes$ early. The distance of Pintu's school from his house is (in $km$):

When Alisha goes by car at $50 \, km/h$,she reaches her office $5 \, minutes$ late. But when she takes her motorbike,she reaches $3 \, minutes$ early. If her office is $25 \, km$ away,what is the approximate average speed at which she rides her motorbike? (in $km/h$)

$A$ man driving at $\frac{3}{4}$ of his original speed reaches his destination $20 \text{ minutes}$ later than the usual time. Then the usual time is (in $\text{minutes}$)