$A$ man travelled a distance of $61 \, km$ in $9 \, h$,partly on foot at the rate of $4 \, km/h$ and partly on bicycle at the rate of $9 \, km/h$. The distance travelled on foot was (in $km$):

$A$ $100\, m$ long train completely passes a man walking in the same direction at $6\, km/h$ in $5\, s$ and also a car travelling in the same direction in $6\, s$. At what speed was the car travelling? (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 $.625$)

$A$ certain distance is covered by a cyclist at a certain speed. If a jogger covers half the distance in double the time,the ratio of the speed of the jogger to that of the cyclist is

Two trains of equal length are running on parallel tracks in the same direction at the speeds of $46 \, km/h$ and $36 \, km/h$. The faster train passes the slower train in $36 \, seconds$. The length of each train is (in $m$):

Ramesh crosses a $600 \, m$ long street in $5 \, \text{minutes}$. His speed in $km/h$ is: