Ramesh crosses a $600 \, m$ long street in $5 \, \text{minutes}$. His speed in $km/h$ is:

$A$ bike covers a certain distance at a speed of $64 \, km/h$ in $8 \, hours$. If the bike were to cover the same distance in approximately $6 \, hours$,at what approximate speed should the bike travel? (in $km/h$)

Two trains are running in opposite directions with the same speed. If the length of each train is $135 \, m$ and they cross each other in $18 \, s$,the speed of each train is (in $km/h$):

Two men $A$ and $B$ walk from $P$ to $Q$ at a distance of $21 \text{ km}$ at speeds of $3 \text{ km/h}$ and $4 \text{ km/h}$ respectively. $B$ reaches $Q$ and returns immediately and meets $A$ at $R$. The distance from $P$ to $R$ is (in $\text{km}$):

$A$ train travels at a speed of $10\, m/s$ and leaves Trivandrum for Nagercoil at $8\, AM$. At what distance from Nagercoil will it meet a train which leaves Nagercoil for Trivandrum at $8.20\, AM$ and travels one-third faster than the former? The distance from Trivandrum to Nagercoil is $68\, km$. (in $km$)

$A$ train runs at an average speed of $75\, km/hr$. If the distance to be covered is $1050\, km$, how long will the train take to cover it? (in $hrs$)