Question

If

A * B means 'A multiplied by B';

A @ B means 'A minus B';

A $ B means 'A plus B';

A # B means 'A divided by B',

then what will be the total area of 21 circles, each with the same radius of r cm?

• A. 22 * r * 7 * r # 21
• B. 22 # 21 * r * r
• C. 66 * r${}^2$ # 7
• D. 66 * r * r

Answer 1

The correct option is D 66 * r * r

Area of 21 circles each has radius r cm is$=21\times \pi r^2$
$=21\times \frac{22}{7}\times r^2$
$=66\times r\times r$
hence option D is answer.