Question

Rahul's dad was seeing the plan for their new house, the outline of the house is shown in the figure,

Rahul's Dad asked him to find the value of "$x$" if the perimeter of the outline is 101 m.

$x$ is equal to

• A. 9
• B. 10
• C. 11
• D. 12

Answer 1

The correct option is B

10

The perimeter of the outline is the sum of the length of all the sides.
Perimeter = $(x+2)+(2x+1)+(2x+10)+(x+2)+(x+3)+(x+3)$
Group the variable and numbers,
$\Rightarrow (x+2x+2x+x+x+x)+(2+1+10+2+3+3)=\left(8x\right)+\left(21\right)$
Given that, perimeter is equal to 101 m
$\Rightarrow 8x+21=101$
Subtract 21 from both sides give,
$\Rightarrow 8x+21-21=101-21$
$\Rightarrow 8x=80$
Divide both sides by 8,
$\Rightarrow \frac{8x}{8}=\frac{80}{8}$
$\Rightarrow x=10$