Question

A room is $5\text{m}40\text{cm}$ long and $4\text{m}50\text{cm}$ broad. Its area is:

• A. $\begin{array}{rcl}& & 24.3{\text{m}}^2\end{array}$
• B. $34.3{\text{m}}^2$
• C. $25{\text{m}}^2$
• D. $98.01{\text{m}}^2$

Answer 1

The correct option is A

$\begin{array}{rcl}& & 24.3{\text{m}}^2\end{array}$

The area $A$ of the rectangle with length $l$ and width $w$ is given by, $A=l\times w$.

Step 1: Convert the dimensions into the meter.

$\begin{array}{rcl}l& =& 5\text{m}40\text{cm}\\ & =& 5\text{m}\frac{40}{100}\text{m}\\ & =& 5.4\text{m}\end{array}$:

$\begin{array}{rcl}w& =& 4\text{m}50\text{cm}\\ & =& 4\text{m}\frac{50}{100}\text{m}\\ & =& 4.5\text{m}\end{array}$

Step 2: Substitute $l=5.4$, $w=4.5$ into $A=l\times w$ and find the area of the room.

$\begin{array}{rcl}A& =& 5.4\times 4.5\\ & =& 24.3{\text{m}}^2\end{array}$

Hence, the correct option is $\mathit{a}$.