$A$ motor car starts with a speed of $70 \, km/hr$ with its speed increasing every $2 \, hours$ by $10 \, km/hr$. In how many hours will it cover $345 \, km$?

Two trains,one $160 \, m$ and the other $140 \, m$ long,are running in opposite directions on parallel tracks. The first is moving at $77 \, km/h$ and the other at $67 \, km/h$. How long will they take to cross each other? (in $seconds$)

The speed of a train going from Nagpur to Allahabad is $100 \text{ km/h}$,while its speed is $150 \text{ km/h}$ when coming back from Allahabad to Nagpur. What is the average speed during the whole journey in $\text{km/h}$?

$A$ train running at $\frac{7}{11}$ of its normal speed reached a place in $22\, \text{hours}$. How much time could be saved if the train had run at its normal speed? (in $\text{hours}$)

$A$ man walks $6 \, km$ at a speed of $1 \frac{1}{2} \, km/h$,runs $8 \, km$ at a speed of $2 \, km/h$,and travels another $32 \, km$ by bus. The speed of the bus is $8 \, km/h$. Find the average speed of the man in $km/h$.

$A$ bicycle rider covers his onward journey from $A$ to $B$ at $10 \text{ km/h}$ and during the return journey from $B$ to $A$ he covers the same distance at $8 \text{ km/h}$. If he finishes the onward and return journey in $4 \frac{1}{2} \text{ hours}$,then the total distance covered by him during the entire journey is (in $\text{km}$)