A train $X$ takes $50 \mathrm{s}$ to cross a $400 \mathrm{m}$ long train moving at a speed of $20 \mathrm{m}/\mathrm{s}$. It would take $100 \mathrm{s}$ to cross a pole. Find the speed of the train $X$ (in $\mathrm{m}/\mathrm{s}$).

A person covers $20 \mathrm{km}$ in a certain time. He travels four successive distances of $5 \mathrm{km}$ each at respective speeds of $10 \mathrm{kmph}, 20 \mathrm{kmph}, 30 \mathrm{kmph} \text{and} 60 \mathrm{kmph}$. Find the time taken to cover the total distance.

Find the time taken by a train of length $360 \mathrm{m}$ travelling at $72 \mathrm{km}/\mathrm{hr}$ to cross an electric pole (in $\mathrm{seconds}$).

A train $T$ travelling at a speed of $54 \mathrm{kmph}$ passes an electric pole in $20 \mathrm{s}$. Find the time taken by it to cross a bridge of length $900 \mathrm{m}$ (in $\mathrm{seconds}$).

In a $1500 \mathrm{m}$ race, $P$ beats $Q$ by $100 \mathrm{m}$ and $P$ beats $R$ by $240 \mathrm{m}$. By what distance does $Q$ beat $R$ in the same race?

Find the time taken by a train of length $100 \mathrm{m}$ running at a speed of $72 \mathrm{kmph}$ to cross another train of length $200 \mathrm{m}$ running at a speed of $63 \mathrm{kmph}$ in the same direction.

A train took $20 \mathrm{s}$ to cross a stationary pole when travelling at $72 \mathrm{kmph}$. In how many seconds can it cross a $500 \mathrm{m}$ long bridge?

In a $1000 \mathrm{m}$ race, $A$ beats $B$ by $100 \mathrm{m}$ and in the same race, $A$ beats $C$ by $190 \mathrm{m}$. Find by what distance does $B$ beat $C$ in the same race?

A train of length $300 \mathrm{m}$ takes $20 \mathrm{s}$ to overtake a cyclist travelling at $18 \mathrm{kmph}$. Find its speed (in $\mathrm{m}/\mathrm{s}$).