Walking $\frac{6}{7}$ of his usual speed, a man is $12 \, \text{minutes}$ late. The usual time taken by him to cover that distance is

$A$ $300 \, m$ long train is travelling with a speed of $45 \, km/hr$ when it passes point $A$ completely. At the same time,a motorbike starts from point $A$ with a speed of $70 \, km/hr$. When it exactly reaches the middle point of the train,the train increases its speed to $60 \, km/hr$ and the motorbike reduces its speed to $65 \, km/hr$. How much distance will the motorbike travel while passing the train completely? (in $km$)

$A$ motor car completes a journey in $10 \, hours$. It covers the first half of the distance at $21 \, km/h$ and the remaining half at $24 \, km/h$. Find the total distance (in $km$).

$A$ boy goes to his school from his house at a speed of $3 \text{ km/hr}$. If he takes $5 \text{ hours}$ in total for going and coming back,the distance between his house and school is (in $\text{km}$):

$A$ $110 \text{ meters}$ long train passes a man walking at the speed of $6 \text{ km/h}$ against it in $6 \text{ seconds}$. The speed of the train in $\text{km/h}$ is:

$A$ motorcyclist travels from Mumbai to Pune,a distance of $192 \, km$,at an average speed of $32 \, km/h$. Another man starts from Mumbai by travelling in a car,$2 \frac{1}{2} \, hours$ after the motorcyclist and reaches Pune half an hour earlier. What is the ratio of the speeds of the motorcycle and the car?