The wheel of an engine is $3 \frac{3}{4}$ metres in circumference and makes $4$ revolutions in $2$ seconds. The speed of the train is (in $km/h$):

$A$ car moving in the same direction passes a man walking at $4\, km/h$. The man can see the car for $3\, minutes$ and the visibility is up to a distance of $130\, m$. The speed of the car is: (in $km/h$)

Ravi and Ajay start simultaneously from a place $A$ towards $B$,$60 \, km$ apart. Ravi's speed is $4 \, km/h$ less than that of Ajay. Ajay,after reaching $B$,turns back and meets Ravi at a place $12 \, km$ away from $B$. Ravi's speed is (in $km/h$):

$A$ car covers $\frac{1}{5}$ of the distance from $A$ to $B$ at the speed of $8 \, km/h$,$\frac{1}{10}$ of the distance at $25 \, km/h$,and the remaining at the speed of $20 \, km/h$. Find the average speed of the whole journey in $km/h$. (in $.625$)

Train $A$ crosses a pole in $25 \text{ seconds}$ and another Train $B$ crosses a pole in $1 \text{ minute}$ and $15 \text{ seconds}$. The length of Train $A$ is half the length of Train $B$. What is the respective ratio between the speeds of Train $A$ and Train $B$?

$A$ man travelled a distance of $80 \, km$ in $7 \, h$,partly on foot at the rate of $8 \, km/h$ and partly by bicycle at $16 \, km/h$. The distance travelled on foot is (in $km$):