$A$ 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 $345 \, km$?

$A$ car covers four successive $7 \, km$ distances at speeds of $10 \, km/h$,$20 \, km/h$,$30 \, km/h$,and $60 \, km/h$ respectively. Its average speed over this total distance is (in $km/h$):

$A$ man can reach a certain place in $30 \, \text{hours}$. If he reduces his speed by $\frac{1}{15}^{th}$, he goes $10 \, \text{km}$ less in that same time. Find his speed in $\text{km/hr}$.

$A$ 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:

$A$ person crosses a $600\, m$ long street in $5\, minutes$. What is his speed in $km/hr$?

The distance between places $A$ and $B$ is $999 \text{ km}$. An express train leaves place $A$ at $6:00 \text{ am}$ and runs at a speed of $55.5 \text{ km/h}$. The train stops on the way for $1 \text{ hour } 20 \text{ minutes}$. At what time does it reach place $B$ (in $\text{pm}$)?