$A$ $180 \, m$ long train crosses another $270 \, m$ long train running from the opposite direction in $10.8 \, s$. If the speed of the first train is $60 \, km/h$,what is the speed of the second train in $km/h$?

Anna left for city $A$ from city $B$ at $5:20\, a.m.$ She travelled at a speed of $80\, km/h$ for $2\, hours\, 15\, minutes.$ After that,the speed was reduced to $60\, km/h.$ If the total distance between the two cities is $350\, km,$ at what time did Anna reach city $A$?

Buses start from a bus terminal with a speed of $20 \text{ km/h}$ at intervals of $10 \text{ mins}$. What is the speed of a man coming from the opposite direction towards the bus terminal if he meets the buses at intervals of $8 \text{ mins}$? (in $\text{km/h}$)

$A$ man is walking at a speed of $10 \, km/h$. After every $1 \, km$, he takes a rest for $5 \, minutes$. How much time will he take to cover a distance of $5 \, km$? (in $minutes$)

Two trains of equal length take $10 \, s$ and $15 \, s$ respectively to cross a telegraph post. If the length of each train is $120 \, m$,in what time (in $s$) will they cross each other while travelling in the same direction?

$A$ person travels from $P$ to $Q$ at a speed of $40 \, km/h$ and returns from $Q$ to $P$ by increasing his speed by $50\%$. What is his average speed for the entire journey? (in $km/h$)