Question

The length and the breadth of a rectangular sheet are $16.2\text{cm}$ and $10.1\text{cm}$ respectively. The area of the sheet in appropriate significant figures is

• A. $164{\text{cm}}^2$
• B. $163{\text{cm}}^2$
• C. $163.6{\text{cm}}^2$
• D. $163.62{\text{cm}}^2$

Answer 1

The correct option is A $164{\text{cm}}^2$

We know that, the area of a sheet is given by,
$A=lb$, where $l$ is length and $b$ is breadth.
$\Rightarrow A=16.2\times 10.1=163.62{\text{cm}}^2$
We know that in multiplication or division, the final answer should have as many significant figures as in given data with minimum number of significant figures.
Here, both the data have the minimum number of significant figures equal to three. Therefore, the final answer should have three significant figures.
On rounding off $163.62{\text{cm}}^2$ to three significant figures, we get, $164{\text{cm}}^2$.