$A$ car covers a distance of $330 \, km$ in a certain amount of time at a speed of $55 \, km/h$. What is the average speed of a bike that covers a distance of $15 \, km$ less than the car in $1 \, hour$ less than the time taken by the car? (in $km/h$)

$A$ $75 \, m$ long train is moving at $20 \, km/h$. It will cross a man standing on the platform in (in $sec$):

$A$ boy rides his bicycle $10 \, km$ at an average speed of $12 \, km/hr$ and again travels $12 \, km$ at an average speed of $10 \, km/hr$. His average speed for the entire trip is approximately (in $km/hr$)

Two trains of lengths $120 \,m$ and $80 \,m$ are running in the same direction with velocities of $40 \,km/h$ and $50 \,km/h$ respectively. The time taken by them to cross each other is (in $sec$).

Mohan walks from Tilak Nagar to Moti Nagar and back in a certain time at the rate of $3 \frac{1}{2} \, km/h$. But,if he had walked from Tilak Nagar to Moti Nagar at the rate of $3 \, km/h$ and back from Moti Nagar to Tilak Nagar at the rate of $4 \, km/h$,he would have taken $10 \, minutes$ longer. The distance between Tilak Nagar and Moti Nagar is (in $km$)

$A, B$ and $C$ can walk at the rates of $3, 4$ and $5 \text{ km/h}$ respectively. They start from Pune at $1, 2$ and $3 \text{ o'clock}$ respectively. When $B$ catches $A$,$B$ sends him back with a message to $C$. When will $C$ get the message?