Problem: State how many significant figures are proper in the results of the following calculations:

\begin{align*}
\left(a\right)\:\frac{\left(106.7\right)\left(98.2\right)}{\left(46.210\right)\left(1.01\right)} \ \qquad \ \left(b\right)\:\left(18.7\right)^2 \ \qquad \ \left(c\right)\:\left(1.60\times 10^{-19}\right)\left(3712\right)
\end{align*}

Solution:

Part A

The answer is limited by 98.2 and 1.01. They are both 3 significant figures. So, the result should be 3 significant figures.

Part B

The answer is limited by 18.7. The answer should be 3 significant figures. So, the result should be 3 significant figures.

Part C

The answer is limited by 1.60 which is 3 significant figures. So, the result should be 3 significant figures.