Question

Ram says that 22 bags of cement were required to cement a circular platform. If one bag of cement is required to cement an area of 7 m², then the area and the radius of the circular platform respectively are

• A. 154 cm², 7 cm
• B. 154 m², 7 m
• C. 22 cm², 7 cm
• D. 22 m², 7 m

Answer 1

The correct option is B

154 m², 7 m

$\text{Area of circular platform}=\text{Area cemented by 1 bag}\times \text{Number of cement bags used}$

$⟹\text{Area of circular platform}=7\times 22=154m^2$

We know,
area of circle of radius 'r' = π$r^2$

$⟹\frac{22}{7}$ × $r^2=154m^2$
$\therefore r=7m$