$A$ jogger running at $9 \; km/hr$ alongside a railway track is $240 \; m$ ahead of the engine of a $120 \; m$ long train running at $45 \; km/hr$ in the same direction. In how much time (in $sec$) will the train pass the jogger?

$A$ train passes a station platform in $36 \; \text{seconds}$ and a man standing on the platform in $20 \; \text{seconds}$. If the speed of the train is $54 \; \text{km/hr}$, what is the length (in $m$) of the platform?

$A$ train $800 \; m$ long is running at a speed of $78 \; km/hr$. If it crosses a tunnel in $1 \; minute$,then the length (in $m$) of the tunnel is:

Two stations $P$ and $Q$ are $110 \; km$ apart on a straight line. One train starts from $P$ at $7 \; am$ and travels towards $Q$ at $20 \; km/h$ speed. Another train starts from $Q$ at $8 \; am$ and travels towards $P$ at a speed of $25 \; km/h$. At what time will they meet?

$A$ train $100 \; m$ long is running at the speed of $30 \; km/hr$. Find the time (in $sec$) taken by it to pass a man standing near the railway line.

Two trains running in opposite directions cross a man standing on the platform in $27 \;seconds$ and $17 \;seconds$ respectively, and they cross each other in $23 \;seconds$. The ratio of their speeds is