Hello, alibond07!

You need to know the area of a circle and some common sense.

Exactly where is your difficulty?

A circular dartboard is divided into 20 equal sectors,

one of which is shown in the diagram. O is the centre of the circle.

The areas for scoring double and treble are marked A and B respectively.

Find the ratio (area A) : (area B) in the form n : 1, giving n correct to 1 d.p

OM: 99mm . MN: 8mm . OP: 162mm . PQ: 8mm This is a diagram of the radii: Code:

: - - - - 107 - - - :
: - - -99 - - :
(A) (B)
O ----------- M --- N ------- P --- Q
: - - - - - - - 162 - - - - - :
: - - - - - - - - 170 - - - - - - - :

The circle with radius has area: .

The circle with radius has area: .

. . The area of ring is: .

The circle with radius has area: .

The circle with radius has area: .

. . The area of ring is: .

Hence: .

Therefore: .