The radius of a circle is increased in such a way that its circumference increases by 7%. As a result, the area of the circle also increases by:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 14.49%.
Let the original radius of the circle = r
Original circumference = 2πr and Original area (A) = πr2
New circumference = 1.07 × 2πr
New radius = 1.07r
New area (A') = π(1.07r)2 = 1.1449πr2 = 1.1449A
Increase in area = 1.1449A - A = 0.1449A
Percentage Increase = (0.1449A/A) × 100% = 14.49%