passwella.
Menu

WAEC Mathematics 2006 Question 33

Question 33

Mensuration of Plane Shapes

In the diagram, the two circles have a common centre O. If the area of the larger circle is 100π and that of the smaller circle is 49π, find x.

Diagram for this question
  1. A.2
  2. B.3
  3. C.4
  4. D.6
Show the answer and explanation

Answer: B (3)

Explanation

πR2 = 100π gives R = 10 and πr2 = 49π gives r = 7. x is the gap between the circles: 10 − 7 = 3.