$A$ car covers $\frac{1}{5}$ of the distance from $A$ to $B$ at the speed of $8 \, km/h$,$\frac{1}{10}$ of the distance at $25 \, km/h$,and the remaining at the speed of $20 \, km/h$. Find the average speed of the whole journey in $km/h$. (in $.625$)

An express train travelled at an average speed of $100 \, km/hr$, stopping for $3 \, minutes$ after every $75 \, km$. How long did it take to reach its destination $600 \, km$ from the starting point?

Two trains of equal length are running on parallel tracks in the same direction at the speeds of $46 \, km/h$ and $36 \, km/h$. The faster train passes the slower train in $36 \, seconds$. The length of each train is (in $m$):

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

$A$ car during its journey travels $30 \text{ minutes}$ at a speed of $40 \text{ km/h}$,another $45 \text{ minutes}$ at a speed of $60 \text{ km/h}$,and $2 \text{ hours}$ at a speed of $70 \text{ km/h}$. The average speed of the car is (in $\text{km/h}$):

The bus fare for one person is $Rs. 420$ from Agra to Aligarh and the train fare between the same places for one person is equal to $\frac{3}{4}$ of the bus fare for $2$ persons between the same places. What is the total fare paid by $2$ persons traveling by bus and $4$ persons traveling by train between the two places? (in $Rs.$)