$A$ $150 \, m$ long train takes $10 \, s$ to pass over another $100 \, m$ long train coming from the opposite direction. If the speed of the first train is $30 \, km/h$,the speed of the second train is (in $km/h$):

Ravi and Ajay start simultaneously from a place $A$ towards $B$,$60 \, km$ apart. Ravi's speed is $4 \, km/h$ less than that of Ajay. Ajay,after reaching $B$,turns back and meets Ravi at a place $12 \, km$ away from $B$. Ravi's speed is (in $km/h$):

$A$ car travels the first $39 \, km$ distance in $45 \, minutes$ and the next $25 \, km$ distance in $35 \, minutes$. What is its average speed in $km/h$?

The distance between places $A$ and $B$ is $999 \text{ km}$. An express train leaves place $A$ at $6:00 \text{ am}$ and runs at a speed of $55.5 \text{ km/h}$. The train stops on the way for $1 \text{ hour } 20 \text{ minutes}$. At what time does it reach place $B$ (in $\text{pm}$)?

$A, B$ 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?

If a person walks at $14 \, km/h$ instead of $10 \, km/h$,he would have walked $20 \, km$ more. The actual distance travelled by him is (in $km$):