$A$ 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 $m/sec$):

$A$ speed of $45\, km/h$ is equivalent to which speed in $m/s$?

Two buses start at the same time from two bus stations and proceed towards each other at the rates of $20 \, km/h$ and $25 \, km/h$ respectively. When they meet,one bus has travelled $80 \, km$ more than the other. Find the distance between the two bus stations (in $km$).

Two trains started at the same time,one from $A$ to $B$ and the other from $B$ to $A$. If they arrived at $B$ and $A$ respectively $4 \ hours$ and $9 \ hours$ after they passed each other,the ratio of the speeds of the two trains was:

Two trains are moving in the same direction at $50 \, km/h$ and $30 \, km/h$. The faster train crosses a man in the slower train in $18 \, seconds$. Find the length of the faster train (in $m$).

$A$ car driver leaves Bangalore at $8:30 \, am$ and expects to reach a place $300 \, km$ from Bangalore at $12:30 \, pm$. At $10:30 \, am$, he finds that he has covered only $40 \%$ of the distance. By how much does he have to increase the speed of the car in order to keep up with his schedule? (in $km/h$)