Ramesh crosses a $600 \, m$ long street in $5 \, \text{minutes}$. His speed in $km/h$ is:

Walking at the rate of $4 \, km/h$, a man covers a certain distance in $2 \, \text{hours} \, 45 \, \text{minutes}$. Running at a speed of $16.5 \, km/h$, the man will cover the same distance in how many minutes?

$A$ walks around a circular field at the rate of one $round/hour$,while $B$ runs around it at the rate of six $rounds/hour$. They start in the same direction from the same point at $7.30 \, a.m$. They shall first cross each other at (in $a.m.$)

Walking at three-fourth of his usual speed, a man covers a certain distance in $2 \, \text{hours}$ more than the time he takes to cover the distance at his usual speed. The time taken by him to cover the distance with his usual speed is (in $\text{hours}$):

$A$ 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 $\text{km/hr}$.

$A$ $300 \, m$ 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 $km$)