Let the radius of smaller circle be r

Let the radius of bigger circle be 2r

Now if the to complete the bigger circle the entire diameter will be 4 times that of the smaller circle. hence its 4.

Two circular road signs are to be painted yellow. If the radius of the larger sign is twice that of the smaller sign, how many times more paint is needed to paint the larger sign (assuming that a given amount of paint covers the same area on both signs)

How many times more paint need means to cover the entire area, thus we just need to know area.

Dear skamal

You see you need to understand the difference between circumference and area visually first.
if you draw a circle on paper then:-
the boundary of circle called circumference . it formula is 2*pie*radius

the space covered inside the closed boundary and also the space covered by the drawing of boundary(how so ever small it is) is called area..

Now you need to draw sign.
Unless stated otherwise, you can safely assume that you draw fully filled circle and not a empty circle.

Hope it helps
Kudos please if you like it.

Hi,
I also followed the same approach but since in the question it was asked that how many times more paint is needed to paint the larger sign..
I subtracted the larger circle with that of the smaller circle. so the answer I got was 4-1 =3.

I feel for the answer to be 4 the question, the word more should have been omitted would have been something like
the paint on the larger cirlce would be how many times that of the smaller circle

Can somebody clear this doubt?

I had the same query as Suramya and Cool Naren. could someone explain why the answer is 4 and not 3?