$A$ person travelled a certain distance by train at a speed of $25\, km/h$ and walked back at a speed of $4\, km/h$. The whole journey took $5\, hours\, 48\, minutes$. What distance did he travel? (in $km$)

$A$ person has to cover a distance of $6 \, km$ in $45 \, minutes$. If he covers one-half of the distance in two-third of the total time,to cover the remaining distance in the remaining time,his speed (in $km/hr$) must be:

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

Two trains $A$ and $B$ start at the same time from Delhi and Patna respectively towards each other. They meet after $16 \, h$. If the distance between Delhi and Patna is $1872 \, km$ and train $B$ runs $27 \, km/h$ faster than train $A$,what is the speed of train $A$ in $km/h$?

The ratio between the speed of a bike and a train is $15:27$ respectively. Also,a bus covers a distance of $720 \, km$ in $9 \, hours$. The speed of the bike is three-fourths the speed of the bus. How much distance will the train cover in $7 \, hours$? (in $km$)

$A$ 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 $a.m.$)