$A$ student walks from his house at a speed of $2 \frac{1}{2} \text{ km/h}$ and reaches his school $6 \text{ min}$ late. The next day,he increases his speed by $1 \text{ km/h}$ and reaches $6 \text{ min}$ before school time. How far is the school from his house? (in $\text{km}$)

The average speed of a car is $1 \frac{4}{5}$ times the average speed of a bus. $A$ tractor covers $575 \text{ km}$ in $23 \text{ hours}$. How much distance will the car cover in $4 \text{ hours}$ if the speed of the bus is twice the speed of the tractor? (in $\text{km}$)

$A$ car starts with a speed of $70 \, km/h$ and its speed increases by $10 \, km/h$ every two hours. In how many hours will it cover $345 \, km$?

The distance between places $A$ and $B$ is $999 \, km$. An express train leaves place $A$ at $6 \, am$ and runs at a speed of $55.5 \, km/h$. The train stops on the way for $1 \, hr \, 20 \, min$. It reaches $B$ at?

Two trains,Kanpur Mail and Delhi Mail,start at the same time from stations Kanpur and Delhi respectively towards each other. After passing each other,they take $12\, \text{hours}$ and $3\, \text{hours}$ to reach Delhi and Kanpur respectively. If the Kanpur Mail is moving at the speed of $48\, \text{km/hr}$,the speed of the Delhi Mail is (in $\text{km/hr}$):

$A$ person has to cover a distance of $6 \, km$ in $45 \, minutes$. If he covers one-half of the distance in two-third of the total time,to cover the remaining distance in the remaining time,his speed (in $km/hr$) must be: