Question

The length of a rectangular notebook is 15 cm and the perimeter is 50 cm. Find the width and area of the notebook.

• A. $8\text{cm}$, $150{\text{cm}}^2$
• B. $9\text{cm}$, $100{\text{cm}}^2$
• C. $10\text{cm}$, $150{\text{cm}}^2$
• D. $11\text{cm}$, $1500{\text{cm}}^2$

Answer 1

The correct option is C $10\text{cm}$, $150{\text{cm}}^2$

Let the breadth of the notebook be y cm.
Length = 15 cm (Given)
Perimeter = 50 cm (Given)
Perimeter of the rectangular notebook = Sum of the lengths of its four sides.
$\Rightarrow$ 50 = 15 + 15 + y + y
$\Rightarrow$ 50 =2(15 +y)
$\Rightarrow$ 25 = (15 + y)
$\Rightarrow$ y = 10 cm
The width of notebook is 10 cm

Area covered by the notebook $=15\text{cm}\times 10\text{cm}=150{\text{cm}}^2$