$A$ train leaves the station $1 \, hr$ before the scheduled time. The driver decreases its speed by $4 \, km/hr$. At the next station $120 \, km$ away,the train reaches on time. Find the original speed of the train in $km/hr$.

$A$ carriage driving in a fog passed a man who was walking at the rate of $3 \text{ km/h}$ in the same direction. He could see the carriage for $4 \text{ minutes}$ and it was visible to him up to a distance of $100 \text{ m}$. What was the speed of the carriage in $\text{km/h}$?

$A$ man starts running from point $P$ at $11:00$ $a.m.$ with a speed of $10 \, km/hr$. He runs for $2 \, hours$ and then takes a $1 \, hour$ rest. He continues this pattern until he is caught by another man who starts at $2:00 \, p.m.$ from point $P$ and runs non-stop at a speed of $15 \, km/hr$ toward the first man. At what time (in $p.m.$) will the first man be caught?

$A$ train covers a distance of $12 \, km$ in $10 \, minutes$. If it takes $6 \, seconds$ to pass a telegraph post,then the length of the train is (in $meters$):

$A$ $320\, m$ long train moving at an average speed of $120\, km/h$ crosses a platform in $24\, seconds$. $A$ man crosses the same platform in $4\, minutes$. What is the speed of the man in $m/s$?

$A$ man walks at the rate of $5 \, km/hr$ for $6 \, hours$ and at $4 \, km/hr$ for $12 \, hours$. The average speed of the man (in $km/hr$) is: