Answer
$1.2\times 10^{-2}$
Work Step by Step
Scientific notation has the form : $A\times 10^{n}$,
where A is a number between 1 and 10, $ 1\leq A<10$.
$\displaystyle \frac{24\times 10^{3}}{2\times 10^{6}}=\frac{24}{2}\cdot\frac{10^{3}}{10^{6}}\quad$... use the rule:$ \displaystyle \frac{a^{m}}{a^{n}}=a^{m-n}$
$=12\times 10^{3-6}$
$=12\times 10^{-3}$
... 12 is not between 1 and 10, multiply with $10^{-1}\cdot 10^{1}$
$=(12\cdot 10^{-1})\cdot(10^{1}\times 10^{-3})\quad$... use the rule: $a^{m}\cdot a^{n}=a^{m+n}$
= $1.2\times 10^{-2}$