$A$ man travels $600 \, km$ by train at $80 \, km/hr$, $800 \, km$ by ship at $40 \, km/hr$, $500 \, km$ by aeroplane at $400 \, km/hr$, and $100 \, km$ by car at $50 \, km/hr$. What is the average speed for the entire distance? (in $km/hr$)

$A$ man walks at the rate of $5 \, km/hr$ for $6 \, hours$ and at $4 \, km/hr$ for $12 \, hours$. The average speed of the man (in $km/hr$) is:

$A$ policeman starts to chase a thief. When the thief goes $10 \, \text{steps}$, the policeman moves $8 \, \text{steps}$. $5 \, \text{steps}$ of the policeman are equal to $7 \, \text{steps}$ of the thief. The ratio of the speeds of the policeman and the thief is

Two trains of lengths $120 \,m$ and $80 \,m$ are running in the same direction with velocities of $40 \,km/h$ and $50 \,km/h$ respectively. The time taken by them to cross each other is (in $sec$).

$A$ truck covers a distance of $550\, m$ in $1\, minute,$ whereas a bus covers a distance of $33\, km$ in $45\, minutes.$ The ratio of their speeds is

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 $\text{km/h}$)