$A$ $280 \, m$ long train moving with an average speed of $108 \, km/h$ crosses a platform in $12 \, seconds$. $A$ boy crosses the same platform in $10 \, seconds$. What is the speed of the boy in $m/s$?

In a flight of $600 \, km$,an aircraft was slowed down due to bad weather. Its average speed for the trip was reduced by $200 \, km/hr$ and the time of flight increased by $30 \, minutes$. The duration of the flight is (in $hour$):

$A$ train passes two persons walking in the same direction at a speed of $3 \, km/h$ and $5 \, km/h$ respectively in $10 \, s$ and $11 \, s$ respectively. The speed of the train is (in $km/h$):

$A$ train,$300 \, m$ long,passes a man walking along the line in the same direction at the rate of $3 \, km/h$ in $33 \, s$. The speed of the train is (in $km/h$):

$A$ car travels $10\, m$ in $1$ second. Find its speed in $km/h$.

$A$ train leaves a station $A$ at $7:00 \text{ am}$ and reaches another station $B$ at $11:00 \text{ am}.$ Another train leaves station $B$ at $8:00 \text{ am}$ and reaches $A$ at $11:30 \text{ am}.$ At what time do the two trains cross each other?