$A$ boy takes as much time in running $12 \, m$ as a car takes in covering $36 \, m$. The ratio of the speeds of the boy and the car is

$A$ starts from a place $P$ to go to a place $Q$. At the same time $B$ starts from $Q$ to $P$. If after meeting each other $A$ and $B$ took $16$ and $25$ $hours$ more respectively to reach their destinations,the ratio of their speeds is

$A$ man walking at the rate of $5\, km/hr$ crosses a bridge in $15\, minutes$. The length of the bridge (in $meters$) is:

$A$ train $200 \, m$ long is running at a speed of $20 \, m/s$. In how much time (in $seconds$) will it cross a bridge of $400 \, m$ length?

Paschim Express left Delhi for Mumbai at $14:30\, \text{hours}$ travelling at a speed of $60\, \text{km/h}$. August Kranti Express left Delhi for Mumbai on the same day at $16:30\, \text{hours}$ travelling at a speed of $80\, \text{km/h}$. How far away from Delhi will the two trains meet (stoppages excluded)? (in $\text{km}$)

$A$ bus moving at a speed of $45 \, km/h$ overtakes a truck $150 \, m$ ahead going in the same direction in $30 \, s.$ The speed of the truck is? (in $km/h$)