Question

How many times smaller is 2 x 10^-12 than 4 x 10^-10?

Answer 1

the ratio is,

$=\frac{4\times10^{-10}}{2\times10^{-12}}$$\begin{gathered} =2\times10^{12-10} \\ =2\times10^2 \\ =200 \end{gathered}$

so 2 x 10 ^-12 is 200 times smaller than 4 x 10 ^-10