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 $km/h$)

What is the length of the bridge (in $m$) that a man riding at $15 \, km/h$ can cross in $5 \, minutes$?

$A$ man travels $360 \, km$ in $4 \, hrs$,partly by air and partly by train. If he had travelled all the way by air,he would have saved $\frac{4}{5}$ of the time he was in train and would have arrived at his destination $2 \, hrs$ early. Find the distance he travelled by train (in $km$).

$A$ car driver leaves Bangalore at $8:30 \, am$ and expects to reach a place $300 \, km$ from Bangalore at $12:30 \, pm$. At $10:30 \, am$, he finds that he has covered only $40 \%$ of the distance. By how much does he have to increase the speed of the car in order to keep up with his schedule? (in $km/h$)

$A$ train $150 \, m$ long takes $20 \, s$ to cross a platform $450 \, m$ long. The speed of the train in $km/h$ is:

In what time will a train $100 \, m$ long cross an electric pole,if its speed is $144 \, km/h$? (in $seconds$)