Answer
$9.375\cdot 10^{2}$
Work Step by Step
$(1.5\cdot 10^{-3})\div(1.6\cdot 10^{-6})\qquad$...write as fraction.
$=\displaystyle \frac{1.5\cdot 10^{-3}}{1.6\cdot 10^{-6}}\qquad$... write powers as a separate fraction.
$=\displaystyle \frac{1.5}{1.6}\cdot\frac{10^{-3}}{10^{-6}}\qquad$...apply The Quotient Rule $\displaystyle \frac{a^{m}}{a^{n}}=a^{m-n}$
$=\displaystyle \frac{1.5}{1.6}\cdot 10^{-3-(-6)}\qquad$...simplify.
$=0.9375\cdot 10^{3}\qquad$...substitute $9.375\cdot 10^{-1}$ for $0.9375$
$=9.375\cdot 10^{-1}\cdot 10^{3}\qquad$...apply The Product Rule $a^{m}\cdot a^{n}=a^{m+n}$
$=9.375\cdot 10^{2}$