Question

Ratio of the length to the breadth of a rectangle is 3 : 2. If the perimeter of the rectangle is 30 cm, then, its length is cm.

• A. 6
• B. 9
• C. 8

Answer 1

The correct option is B 9

Given, ratio of the length to the breadth = 3 : 2
also, perimeter = 30 cm

$\text{let, the common ratio}=n$
Therefore,
$\text{length}=3n\text{breadth}=2n$

$\because \text{perimeter}=2\times (l+b)$
$\Rightarrow 30=2\times (3n+2n)$
$\Rightarrow 5n=15$
$\Rightarrow n=3$

$\therefore \text{length}=3\times 3=9cm$