$A$ train $300 \ m$ long is running with a speed of $54 \ km/h$. In what time will it cross a telephone pole? (in $seconds$)

$A$ man starts from a place $P$ and reaches the place $Q$ in $7 \, hours$. He travels $\frac{1}{4}^{th}$ of the distance at $10 \, km/h$ and the remaining distance at $12 \, km/h$. The distance,in $km$,between $P$ and $Q$ is

$A$ boy is running at a speed of $p \, km/h$ to cover a distance of $1 \, km$. However,due to the slippery ground,his speed is reduced by $q \, km/h$ $(p > q)$. If he takes $r$ hours to cover the distance,then:

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

Compare the speed of two trains,one moving at the speed of $80 \, km/h$ and the other at $10 \, m/s$.

$A$ train,after travelling $50 \, km$,meets with an accident and then proceeds at $\frac{3}{4}$ of its former speed and arrives at its destination $35 \, minutes$ late. Had the accident occurred $72 \, km$ further,it would have reached the destination only $15 \, minutes$ late. The normal speed of the train (in $km/hr$) is: