$A$ train travelling at a speed of $55\, km/hr$ travels from place $X$ to place $Y$ in $4\, hours$. If its speed is increased by $5\, km/hr$,then the time of journey is reduced by (in $minutes$):

$A$ person 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 travels first $50 \, km$ at $25 \, kmph$, next $40 \, km$ at $20 \, kmph$, and then $90 \, km$ at $15 \, kmph$. His average speed for the whole journey (in $kmph$) is:

$A$ $75 \, m$ long train is moving at $20 \, km/h$. It will cross a man standing on the platform in (in $sec$):

Heena and Renu are competing in a $100\, m$ race. Initially,Heena runs at twice the speed of Renu for the first $50\, m$. After the $50\, m$ mark,Heena runs at $\frac{1}{4}$ of her initial speed,while Renu continues to run at her original speed. If Renu catches up with Heena at a distance of $N$ meters from the finish line,then $N$ is equal to (in meters).

$A, B$ and $C$ can walk at the rates of $3, 4$ and $5 \text{ km/h}$ respectively. They start from Pune at $1, 2$ and $3 \text{ o'clock}$ respectively. When $B$ catches $A$,$B$ sends him back with a message to $C$. When will $C$ get the message?