Walking at three-fourth of his usual speed, a man covers a certain distance in $2 \, \text{hours}$ more than the time he takes to cover the distance at his usual speed. The time taken by him to cover the distance with his usual speed is (in $\text{hours}$):

The average speed of a car is $1 \frac{4}{5}$ times the average speed of a bus. $A$ tractor covers $575 \, km$ in $23 \, hours$. How much distance will the car cover in $4 \, hours$ if the speed of the bus is twice the speed of the tractor? (in $km$)

$A, B$ and $C$ can walk at the rates of $3, 4$ and $5 \text{ km/h}$ respectively. They start from Pune at $1, 2$ and $3 \text{ o'clock}$ respectively. When $B$ catches $A$,$B$ sends him back with a message to $C$. When will $C$ get the message?

$A$ car travels $20\%$ slower than a train. Both start from point $A$ at the same time and reach point $B$ $240\, km$ away at the same time. On the way,the train takes $48\, minutes$ for stopping at stations. What is the speed (in $km/hr$) of the car?

$A$ 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 $km$).

If a distance of $50\, m$ is covered in $1\, minute$,$90\, m$ in $2\, minutes$,and $130\, m$ in $3\, minutes$,find the total distance covered in $15\, minutes$ (in $m$).