The train fare between Patna and Munger for one adult is three times the train fare of one child. If the adult fare is $102$,what will be the total fare for $2$ adults and $3$ children for the same distance?

$A$ passenger train running at the speed of $80 \text{ km/h}$ leaves the railway station $6 \text{ hours}$ after a goods train leaves and overtakes it in $4 \text{ hours}$. What is the speed of the goods train? (in $\text{km/h}$)

$A$ train covers a distance of $10 \text{ km}$ in $12 \text{ minutes}$. If its speed is decreased by $5 \text{ km/hr}$,the time taken by it to cover the same distance will be:

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:

$A$ 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 $.625$)

$P$ and $Q$ are $27 \, km$ apart. Two trains with speeds of $24 \, km/h$ and $18 \, km/h$ respectively start simultaneously from $P$ and $Q$ and travel in the same direction. They meet at a point $R$ beyond $Q$. The distance $QR$ is (in $km$):