$A$ truck covers $224 \ km$ in $4 \ hours$. The average speed of a bike is $\frac{1}{4}$ of the average speed of the truck. How much distance will the bike cover in $7 \ hours$? (in $km$)

If a $200 \, m$ long train crosses a platform of the same length as that of the train in $20 \, s$,then the speed of the train is (in $km/hr$).

$A$ train travels $225 \ km$ in $3.5 \ hours$ and $370 \ km$ in $5 \ hours.$ Find out the average speed of the train in $km/h$.

$50$ trees are standing in a line such that the distance between any two consecutive trees is the same. $A$ car takes $18 \, seconds$ to travel from the $13^{th}$ tree to the $34^{th}$ tree. How much time (in $seconds$) will it take to reach from the first tree to the $50^{th}$ tree?

The distance between two cities $A$ and $B$ is $330\, km$. $A$ train starts from $A$ at $8\, a.m.$ and travels towards $B$ at $60\, km/hr$. Another train starts from $B$ at $9\, a.m.$ and travels towards $A$ at $75\, km/hr$. At what time do they meet? (in $a.m.$)

$A$ motorcyclist left $6 \frac{2}{3}$ minutes later than the scheduled time,but in order to reach his destination $21 \, km$ away on time,he had to increase his speed by $12 \, km/h$ from his usual speed. What is the usual speed (in $km/h$) of the motorcyclist?