UPSC 2016 CDS I Math Paper

Let the radius of each disc be r cm.Length of each side of the square = 2r
Area of the empty space enclosed = Area of the square – 4 × Area of each quadrant of the circle
∴(2r)2−4×

1

4

πr2=

150

847

⇒(4−

22

7

)r2=

150

847

⇒r2=

150×7

847×6

=

25

121

⇒r=

5

11

cm