$A$ 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:

In what time (in $sec$) will a train $100 \; m$ long cross an electric pole,if its speed is $144 \; km/hr$?

Length of a train and that of a platform are equal. If with a speed of $135 \; km/hr$,the train crosses the platform in $40 \; seconds$,then the length (in $m$) of the train is:

Two trains, one from Howrah to Patna and the other from Patna to Howrah, start simultaneously. After they meet, the trains reach their destinations after $9 \; \text{hours}$ and $16 \; \text{hours}$ respectively. The ratio of their speeds is

Two trains $100 \; m$ and $120 \; m$ long are running in the same direction with speeds of $72 \; km/h$ and $54 \; km/h$. In how much time will the faster train cross the second (in $; s$)?

Two trains $140 \; m$ and $160 \; m$ long run at a speed of $60 \; km/hr$ and $40 \; km/hr$ respectively in opposite directions on parallel tracks. The time (in $seconds$) which they take to cross each other is: