Question

How many plants will be there in a circular bed whose outer edge measures $30$cm, allowing $4c{m}^2$ for each plant?

• A. $18$
• B. $750$
• C. $24$
• D. $120$

Answer 1

The correct option is A $18$

The outer edge of the bed$=2\pi r=$ Circumference

$\Rightarrow 2\pi r=30cm$

$\Rightarrow r=\frac{30\times 7}{2\times 22}=4.77cm$

$\therefore$Area of circular bed$=\pi r^2=\frac{22}{7}\times 4.77\times 4.77=71.44c{m}^2$

No. of plants$=\frac{71.44}{4}=17.86\approx 18$