Question

$0.0000851$ =

• A. $8.51\times {10}^{-5}$
• B. $8.15\times {10}^{-5}$
• C. $85.1\times {10}^5$
• D. $8.51\times {10}^{-4}$

Answer 1

The correct option is A $8.51\times {10}^{-5}$

$0.0000851=\frac{851}{10000000}$
$=\frac{8.51\times {10}^2}{{10}^7}$
$=8.51\times {10}^{-5}(\because \frac{a^m}{a^n}=a^{m-n})$