Question

A drain cover is made from a square metal plate of side 40 cm by having 441 holes of radius 1 cm each drilled in it. Find the area in $c{m}^2$ of the remaining square plate. $Use\pi =\frac{22}{7}$

• A. 215
• B. 250
• C. 200
• D. 300

Answer 1

The correct option is A

215

Area of square plate
$={40}^2=1600c{m}^2$

Total area of circles
$=441\times \pi \times 1^2=441\times \frac{22}{7}=1386c{m}^2$

Remaining area
$=1600-1386=214c{m}^2$