The speed of a car increases by $2\, km/h$ after every hour. If the distance travelled in the first hour was $35\, km$,what is the total distance travelled in $12$ hours? (in $km$)

Two trains,$A$ and $B,$ start from stations $X$ and $Y$ towards $Y$ and $X$ respectively. After passing each other,they take $4\, \text{hours } 48\, \text{minutes}$ and $3\, \text{hours } 20\, \text{minutes}$ to reach $Y$ and $X$ respectively. If train $A$ is moving at $45\, \text{km/h},$ then the speed of train $B$ is (in $\text{km/h}$)

$A$ bus moving at a speed of $45 \, km/h$ overtakes a truck $150 \, m$ ahead going in the same direction in $30 \, s.$ The speed of the truck is? (in $km/h$)

Two trains $M$ and $N$ cross a pole in $25 \text{ seconds}$ and $1 \text{ minute } 15 \text{ seconds}$ respectively. The length of train $M$ is half the length of train $N$. What is the respective ratio between the speed of train $M$ and train $N$?

$A$ and $B$ walk around a circular track. They start at $8\, a.m.$ from the same point in opposite directions. $A$ and $B$ walk at a speed of $2\, \text{rounds per hour}$ and $3\, \text{rounds per hour}$ respectively. How many times shall they cross each other before $9.30\, a.m.$?

Two trains measuring $100\, m$ and $80\, m$ respectively,run on parallel tracks. When travelling in opposite directions,they are observed to pass each other in $9\, s$. When they are running in the same direction at the same speeds as before,the faster train passes the other in $18\, s$. Find the speeds of the two trains in $km/h$.