Question

4. On decreasing the radius of the circle by 30%, its area is decreased by
(a) 30%
(b) 6096
(C) 4596
(d) none of these​

Answer 1

let the radius of circle be R

Area of the circle= 3.14 * R^2

Now, radius is decreased by 30%

New radius of circle would be 0.7R

Hence,

New Area= 3.14*(0.7R)^2

New Area= 0.49 * 3.14*R^2

Therefore, New area of the circle would be 51% less than that of original one. Hence the answer is (d)none of these