Question

The difference between the circumference and the diameter of the circle is $15m$. What is the area of the circle?

• A. $25m^2$
• B. $65m^2$
• C. $38.5m^2$
• D. none of these

Answer 1

The correct option is C $38.5m^2$

Difference between the circumference and the diameter of the circle$=2\pi r-2r=15m$

$\Rightarrow 2\times \frac{22}{7}r-2r=15$

$\Rightarrow \frac{44-14}{7}r=15$

$\Rightarrow \frac{30}{7}r=15$

$\Rightarrow r=\frac{15\times 7}{30}=\frac{7}{2}m$

Area of the circle$=\pi r^2=\frac{22}{7}\times \frac{7}{2}\times \frac{7}{2}$

$=\frac{77}{2}=38.5sq.m$