If we divide a cube with an edge of $1 \mathrm{~m}$ into small cubes with an edge of $1 \mathrm{~mm}$, what will be the height of a column formed by all the small cubes, placed one on top of the other?
(a) $1 \mathrm{~m}$
(b) $1 \mathrm{~km}$
(c) $10 \mathrm{~km}$
(d) $100 \mathrm{~km}$
(e) $1000 \mathrm{~km}$

## Solutions to List 3
Converting meters into millimeters we have: $1 \mathrm{~m}=$ $1000 \mathrm{~mm}$. Thus, the cube was divided into $1000 \times 1000=10^{6}$ small cubes, each with a side of $1 \mathrm{~mm}$. Placing the $10^{6}$ small cubes side by side, we will have a column of length

$$
1000 \times 1000=10^{6} \mathrm{~mm}=10^{6} \times 10^{-3} \mathrm{~m}=10^{3} \mathrm{~m}=1 \mathrm{~km}
$$