Question

The diameter of a circle increased from 25cm to 25.8cm. Find the percentage increase in its circumference.​

Answer 1

3.1% increase

Explanation:

Diameter1=25cm

Radius1=12.5cm

Circumference1=2x22/7x12.5

Diameter2=25.8cm

Radius2=12.9cm

Circumference2=2x22/7x12.9

% increase =Circumference2-Circumference1/Circumference2 x 100%= 2x22/7x12.9-2x22/7x12.5 / 2x22/7x12.9 x100%

12.9-12.5/12.9 x 100%

0.4/12.9 x 100%

4/129 x 100%

3.1%