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

$A$ boy goes to the school with the speed of $3 \, km/h$ and returns with the speed of $2 \, km/h$. If he takes $5 \, hours$ in all,then the distance (in $km$) between the village and the school is:

Walking at three-fourth of his usual speed, a man covers a certain distance in $2 \, \text{hours}$ more than the time he takes to cover the distance at his usual speed. The time taken by him to cover the distance with his usual speed is (in $\text{hours}$):

$A$ car during its journey travels $30 \text{ minutes}$ at a speed of $40 \text{ km/h}$,another $45 \text{ minutes}$ at a speed of $60 \text{ km/h}$,and $2 \text{ hours}$ at a speed of $70 \text{ km/h}$. The average speed of the car is (in $\text{km/h}$):

$A$ 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:

Train $A$ starts its journey from Patna to Hazipur while train $B$ starts from Hazipur to Patna. After crossing each other, they finish their journey in $81\, \text{hours}$ and $121\, \text{hours}$ respectively. What will be the speed of train $B$ if the speed of train $A$ is $44\, \text{km/h}$?