Question

The ratio of the length and the breadth of a rectangle is $3:5$ and its area is $1.35c{m}^2$. Find the length of the rectangle.

• A. $1.5$ cm
• B. $0.9$ cm
• C. $1.3$ cm
• D. $1.4$ cm

Answer 1

The correct option is B $0.9$ cm

Ratio of the length and the breadth of a rectangle is $l:b=3:5$

$\Rightarrow \frac{l}{b}=\frac{3}{5}$

$\Rightarrow b=\frac{5l}{3}$

Given:Area of the rectangle$=l\times b$

$\Rightarrow 1.35{cm}^2=l\times \frac{5l}{3}$

$\Rightarrow 1.35=\frac{5l^2}{3}$

$\Rightarrow 5l^2=1.35\times 3$

$\Rightarrow l^2=\frac{1.35\times 3}{5}=0.27\times 3=0.81‬$

$\Rightarrow l=0.9$cm

Hence, the length of the rectangle is $0.9$ cm