Question

There is a rectangular park whose perimeter is 50 cm. If its length is 10 cm, then its breadth will be

• A. 10 cm
• B. 15 cm
• C. 20 cm
• D. 30 cm

Answer 1

The correct option is B

15 cm

We know that if '$l$' is the length of the rectangle and '$b$' is its breadth, then its perimeter is given by

$P=l+b+l+b=(2\times l)+(2\times b)$

Given $P=50\text{cm}$ and $l=10\text{cm}$

Then,

$P=(2\times l)+(2\times b)$

$⟹b=\frac{P-(2\times l)}{2}$

i.e., $b=\frac{50-(2\times 10)}{2}=15\text{cm}$