If a boy can walk $5 \mathrm{km}$ in 2 hours, how long will he take to walk
a. $7.5 \mathrm{km}$
b. $0.25 \mathrm{km}$ at this speed?

An athlete runs $120 \mathrm{m}$ in $15$seconds, then fill in the blanks in the following table, where $d$ is the distance run in metres in time $t$ seconds.

A train $100 \mathrm{m}$ in length crosses a pole in $5$ seconds. Find its speed in $\frac{\mathrm{km}}{\mathrm{h}}$.

A train is running at $72 \frac{\mathrm{km}}{\mathrm{h}}$ and crosses a $160 \mathrm{m}$ long bridge in $18$ seconds.
Calculate the length of the train.
 

A train is running at $72 \frac{\mathrm{km}}{\mathrm{h}}$ and crosses a $160 \mathrm{m}$ long bridge in $18$ seconds.
 How long will it take to cross a pole?