$A$ gun is fired at a distance of $1.34$ $km$ from Geeta. She hears the sound after $4$ $sec$. The speed at which sound travels is (in $m/sec$):

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

$A$ train $160 \ m$ long passes a standing man in $18 \ s$. The speed of the train is (in $km/h$):

$A$ person covers half of his journey at $30 \text{ km/h}$ and the remaining half at $20 \text{ km/h}$. The average speed for the whole journey is (in $\text{km/h}$)

$A, B$ and $C$ start at the same time in the same direction to run around a circular stadium. $A$ completes a round in $252 \text{ seconds}$,$B$ in $308 \text{ seconds}$ and $C$ in $198 \text{ seconds}$,all starting at the same point. After what time will they next meet at the starting point again?

$A$ man goes from a place $A$ to $B$ at a speed of $12 \, km/hr$ and returns from $B$ to $A$ at a speed of $18 \, km/hr$. The average speed for the whole journey is (in $km/hr$):