How long will a boy take to run round a square field of side $35 \, m$,if he runs at the rate of $9 \, km/hr$ (in $sec$)?

Three men step off together from the same spot. Their steps measure $63 \, cm$,$70 \, cm$,and $77 \, cm$ respectively. The minimum distance each should cover so that all can cover the distance in complete steps is (in $cm$):

$A$ train leaves the station at $5 \, am$ at $60 \, km/h$. Another train leaves the same station at $6.30 \, am$ at $75 \, km/h$ and travels in the same direction as the first train. At what time and at what distance from the station will they meet?

$A$ man travelled from the village to the post office at the rate of $25 \, km/hr$ and walked back at the rate of $4 \, km/hr$. If the whole journey took $5 \, hours \, 48 \, minutes$,find the distance of the post office from the village (in $km$).

$A$ student walks from his house at a speed of $2 \frac{1}{2} \text{ km/h}$ and reaches his school $6 \text{ min}$ late. The next day,he increases his speed by $1 \text{ km/h}$ and reaches $6 \text{ min}$ before school time. How far is the school from his house? (in $\text{km}$)

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: