$A$ train running at $25 \, km/hr$ takes $18 \, seconds$ to pass a platform. Next,it takes $12 \, seconds$ to pass a man walking at $5 \, km/hr$ in the opposite direction. Find the sum of the length of the train and that of the platform (in $m$).

The distance of the sun from the earth is $143,400,000 \text{ km}$. Light travels from the sun to the earth in $7 \text{ minutes}$ and $58 \text{ seconds}$. The velocity of light per second is (in $\times 10^5 \text{ km/sec}$):

$A$ $280\,m$ long train is moving at a speed of $60\,km/h$. The time taken by the train to cross a platform $220\,m$ long is (in $seconds$):

$A$ 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 $a.m.$)

$A$ 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 $\text{km/h}$):

Two buses start at the same time from two bus stations and proceed towards each other at the rates of $20 \, km/h$ and $25 \, km/h$ respectively. When they meet,one bus has travelled $80 \, km$ more than the other. Find the distance between the two bus stations (in $km$).