If the circumference of a circle is increased by 20%, then the area of the circle will be increased by :
Answer & explanation
Correct answer: option 2
Circumference C1 = 2Πr1
C2 = 2Πr2 = 20% more than C1 = 1.2C1
2Πr2 = 1.2*2Πr1
r2 = 1.2r1
Area A1 = Πr12
Area A2 = Πr22 = Π*1.2r1*1.2r1 = 1.44*Πr12 = 44% more than A1
The correct answer is option (2) : 44%