In the diagram, the two circles have a common centre O. If the area of…

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

Correct Answer: Option B

Explanation

area of larger circle = 100(pi)
(pi r^2 = 100pi)
R² = 100
R = 10(Radius)
Area of smaller circle = (49 pi)
(pi r^2 = 49pi)
r² = 49
r = 7(radius)
Since R = x + r
x = R – r
x = 10 – 7 = 3