Answer
a) 13.4
b) 49.3
Work Step by Step
a)
$$\frac{A_{earth}}{A_{moon}}=\frac{4\pi r^2_{earth}}{4\pi r^2_{moon}}=\frac{r^2_{earth}}{r^2_{moon}}=\frac{(6.38\times 10^3km)^2}{(1.74\times 10^3km)^2}=13.4$$
(b)
$$\frac{V_{earth}}{V_{moon}}=\frac{\frac{4}{3}\pi r^3_{earth}}{\frac{4}{3}\pi r^3_{moon}}=\frac{r^3_{earth}}{r^3_{moon}}=\frac{(6.38\times 10^3km)^3}{(1.74\times 10^3km)^3}=49.3$$