Question

A circular disc has a circumference of 16pi meters. if we multiply the radius of the circular disc is by 10, what is the circumference of the new disc?
A. 160pi m

B. 260pi m

C. 413pi m

D. 157pi m

Answer 1

The circumference of the new disc 160Π that is 10 time of old circumference.

Step-by-step explanation:

Given,

Circumference of circular disc = 16Π (pi = Π)

Let, the radius of the circle be 'r'

Formula

The circumference of a circle with r radius = 2 Π r

According to the problem,

2 Π r = 16Π

or, 2r = 16 ( by eliminating the value of Π from both the side)

or, r = 8

Now, we multiply the radius by 10

so, the new radius is 8 X 10 = 80

Now the circumference = 2 Π X 80

= 160Π

Hence, the new circumference also will be 10 times of the older one.