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

$A$ train $360 \; m$ long is running at a speed of $45 \; km/hr$. In what time (in $sec$) will it pass a bridge $140 \; m$ long?

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:

How many seconds will a train $60 \; m$ in length,travelling at the rate of $42 \; km/h$,take to pass another train $84 \; m$ long,proceeding in the same direction at the rate of $30 \; km/h$?

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

How many seconds will a $500 \;m$ long train take to cross a man walking with a speed of $3 \;km/h$ in the same direction as the moving train,if the speed of the train is $63 \;km/h$?