Question

the ratio of the radii of two circles is 2:5. Then the ratio of their circumference is

Answer 1

Let the radii of circles be 2r and 5r respectively

C1 = 2*pi *2r

C1 = 4 pi r


C2 = 2* pi *5r

C2 = 10 pi *r.


C1:C2 = 4pi r / 10 pi *r

= 4/10

= 2/5

= 2:5


Required ratio = 2:5

Answer 2

I think its 2x : 5x...