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 $km$)

If a train,with a speed of $60\, km/hr$,crosses a pole in $30\, seconds$,the length of the train (in $meters$) is

Heena and Renu are competing in a $100\, m$ race. Initially,Heena runs at twice the speed of Renu for the first $50\, m$. After the $50\, m$ mark,Heena runs at $\frac{1}{4}$ of her initial speed,while Renu continues to run at her original speed. If Renu catches up with Heena at a distance of $N$ meters from the finish line,then $N$ is equal to (in meters).

Train $A$ crosses a pole in $25 \text{ seconds}$ and another Train $B$ crosses a pole in $1 \text{ minute}$ and $15 \text{ seconds}$. The length of Train $A$ is half the length of Train $B$. What is the respective ratio between the speeds of Train $A$ and Train $B$?

$A$ train travels at $92.4 \, km/h$. How many metres will it travel in $10 \, minutes$?

$A$ 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?