20. $[\mathbf{1 1}]$ Let $\mathcal{V}$ be the volume enclosed by the graph
$$
x^{2016}+y^{2016}+z^{2}=2016
$$

Find $\mathcal{V}$ rounded to the nearest multiple of ten.
Answer: 360

Let $R$ be the region in question. Then we have
$$
[-1,1]^{2} \times[-\sqrt{2014}, \sqrt{2014}] \subset R \subset[-\sqrt[2016]{2016}, \sqrt[2016]{2016}]^{2} \times[\sqrt{2016}, \sqrt{2016}]
$$

We find some bounds: we have
$$
\sqrt{2016}355
$$
and upper-bounded by
$$
2^{2}\left(1+\frac{0.8}{100}\right)^{2} \cdot 2(45)=360\left(1+\frac{6}{1000}\right)^{2}<365
$$

Thus, $R$ rounded to the nearest ten is 360 .