$A$ boy takes as much time in running $12 \, m$ as a car takes in covering $36 \, m$. The ratio of the speeds of the boy and the car is

Two guns were fired from the same place at an interval of $13 \text{ minutes}$,but a person in a train approaching the place hears the second shot $12 \text{ minutes } 30 \text{ seconds}$ after the first. Find the speed of the train,assuming that sound travels at $330 \text{ m/s}$ (in $\text{km/hr}$).

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

Two trains are running at a speed of $40 \, km/h$ and $20 \, km/h$ respectively in the same direction. The fast train completely passes a man sitting in the slow train in $5 \, seconds$. The length of the fast train is (in $m$):

$A$ train $300 \text{ m}$ long is running at a speed of $90 \text{ km/h}$. How many seconds will it take to cross a $200 \text{ m}$ long train running in the opposite direction at a speed of $60 \text{ km/h}$?

$A$ train,$300 \, m$ long,passes a man walking along the line in the same direction at the rate of $3 \, km/h$ in $33 \, s$. The speed of the train is (in $km/h$):