Two trains of equal length take $10 \, s$ and $15 \, s$ respectively to cross a telegraph post. If the length of each train is $120 \, m$,in what time (in $s$) will they cross each other while travelling in the same direction?

How long will a boy take to run round a square field of side $35 \, m$,if he runs at the rate of $9 \, km/hr$ (in $sec$)?

$A$ 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

$A$ boy started from his house by bicycle at $10:00\, a.m.$ at a speed of $12\, km/hr$. His elder brother started after $1\, hr\, 15\, mins$ by scooter along the same path and caught him at $1:30\, p.m.$ The speed of the scooter will be (in $km/hr$):

$A$ student goes to school at the rate of $2 \frac{1}{2} \text{ km/h}$ and reaches $6 \text{ min}$ late. If he travels at the speed of $3 \text{ km/h}$,he is $10 \text{ min}$ early. The distance (in $\text{km}$) between the school and his house is:

$A$ train covers a distance between station $A$ and station $B$ in $45 \, min$. If the speed of the train is reduced by $5 \, km/h$,then the same distance is covered in $48 \, min$. The distance between stations $A$ and $B$ is? (in $km$)