Question

The length of a rectangular room is 6 m more than its breadth. If half the perimeter is 46 m, find its breadth.

• A. 20

Answer 1

The correct option is A 20
Let $l$ and $b$ be the length and breadth of the room respectively.
Then, the perimeter of the room is $2(l+b)$ metres.

From the question,

$l=6+b$ ...(1)

$\frac{1}{2}\times 2(l+b)=46$

$\Rightarrow l+b=46$ ...(2)

Let's solve these two equations using substitution method.

On substituting the value of $l$ from (1) in (2), we get

$6+b+b=46$

$\Rightarrow$ $6+2b=46$

$\Rightarrow 2b=40$

$\Rightarrow b=20m$

$\Rightarrow l=20+6=26m$

Therefore, breadth of the rectanglar room is 20 m.