Question

How many plants (approximately) will be there in a circular bed whose outer edge measures 88 cm allowing $4c{m}^2$ for each plant?

• A. 154
• B. 135
• C. 155
• D. 156

Answer 1

The correct option is A

154

Given: Outer edge of the circular bed = Circumference = 88 cm
Circumference = $2\pi r$, where $r$ is the radius of the circular bed.
$\Rightarrow$ $2\pi r=88$
$\Rightarrow$ $r=\frac{88\times 7}{2\times 22}$
$\Rightarrow$ $r=14cm$
Area of the circular bed = $\pi r^2$
$\Rightarrow$ Area = $\frac{22}{7}\times 14\times 14$
$\Rightarrow$ Area = 616 cm${}^2$
Number of plants that can be planted in the circular bed = $\frac{Areaofthecircularbed}{Areaoccupiedbyeachplant}$
= $\frac{616}{4}$
= $154$
Therefore, the required numbers of plant is 154