$A$ 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:

$A$ 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:

$A$ train leaves the station at $5 \, am$ at $60 \, km/h$. Another train leaves the same station at $6.30 \, am$ at $75 \, km/h$ and travels in the same direction as the first train. At what time and at what distance from the station will they meet?

Ramesh sees a train passing over a $1 \, km$ long bridge. The length of the train is half that of the bridge. If the train passes the bridge in $2 \, minutes$,the speed of the train is (in $km/h$)

$A$ bus takes $15\, hours$ to travel from Delhi to Chandigarh. The bus travels for one-third of the total time at a speed of $80\, km/h$. It travels for $40\%$ of the remaining time at a speed of $70\, km/h$. It travels for $\frac{2}{3}$ of the remaining time at a speed of $85\, km/h$,and the rest of the time at a speed of $100\, km/h$. What is the total distance covered by the bus?

On a tour,a man travels at the rate of $64 \text{ km/h}$ for the first $160 \text{ km}$,then travels the next $160 \text{ km}$ at the rate of $80 \text{ km/h}$. The average speed in $\text{km/h}$ for the first $320 \text{ km}$ of the tour is: