Chapter 2 - Section 2.5 - Powers of 10 - Exercises - Page 122: 16

$10^9$

$(\frac{10^{-2}}{10^{-5}})^3\longrightarrow$ to raise a power to a power, multiply the exponents $=\frac{10^{-6}}{10^{-15}}^\longrightarrow$ to divide powers subtract the exponents $=10^{-6-(-15)}$ $=10^{-6+15}$ $=10^9$