Question

Choose the option with the proper number of dig figs

Answer 1

Note that in performing division and multiplication with significant figure, the number of significant figures in the answer will follow the least number of significant figures from the given.

4 x 10^5 has 1 significant figure

6 x 10^23 has 1 significant figure

1.2 x 10^2 has 2 significant figures

So the answer should be in 1 significant figure only.

Simplifying the expression :

`\begin{gathered} ((4*10^5)(6*10^(23)))/(1.2*10^2)=(4*6)/(1.2)*10^(5+23-2) \\ \Rightarrow20*10^(26) \end{gathered}`

But 20 has 2 significant figures, so moving the decimal point to the left will give us :

`2*10^(27)`

The answer is C. 2 x 10^27