One third of a certain journey is covered at the rate of $25 \, km/hr$,one-fourth at the rate of $30 \, km/hr$,and the rest at $50 \, km/hr$. The average speed for the whole journey is (in $km/hr$):

$A$ 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

$A$ train running at the speed of $84 \, km/h$ passes a man walking in the opposite direction at the speed of $6 \, km/h$ in $4 \, s$. What is the length of the train (in $meters$)?

Two boys jointly begin to write a booklet containing $817$ lines. The first boy starts with the first line and writes $200$ lines an hour. The second boy starts with the last line,then writes line $816$ and so on,proceeding backwards at the rate of $150$ lines an hour. They will meet on:

$A$ 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:

In covering a certain distance,the speeds of $A$ and $B$ are in the ratio of $3:4$. $A$ takes $30 \text{ minutes}$ more than $B$ to reach the destination. What is the time taken by $A$ to reach the destination (in hours)?