$A$ and $B$ are two towns. $A$ car goes from $A$ to $B$ at a speed of $64 \, km/h$ and returns to $A$ at a slower speed. If its average speed for the whole journey is $56 \, km/h$,find its return speed (in $km/h$).

$A$ student walks from his house at $5 \, km/h$ and reaches his school $10 \, minutes$ late. If his speed had been $6 \, km/h$,he would have reached $15 \, minutes$ early. The distance of his school from his house is (in $km$):

$A$ train leaves station $A$ at $5\, AM$ and reaches station $B$ at $9\, AM$ on the same day. Another train leaves station $B$ at $7\, AM$ and reaches station $A$ at $10.30\, AM$ on the same day. The time at which the two trains cross one another is (in $AM$):

$A$ train $300 \ m$ long is running with a speed of $54 \ km/h$. In what time will it cross a telephone pole? (in $seconds$)

$A$ and $B$ run a kilometer and $A$ wins by $25 \text{ sec}$. $A$ and $C$ run a kilometer and $A$ wins by $275 \text{ m}$. When $B$ and $C$ run the same distance,$B$ wins by $30 \text{ sec}$. The time taken by $A$ to run a kilometer is

Two trains are moving in the same direction at $50 \text{ km/hr}$ and $30 \text{ km/hr}$. The faster train crosses a man sitting in the slower train in $18 \text{ seconds}$. Find the length of the faster train in meters.