Option 4 : It is a mixed fraction

**Given: **

Difference in area between two concentric circles is 528 sq.cm and sum of their diameters is 112 cm.

**Formula used:**

Area of circle, \(A = \pi {r^2}\)

Where r = radius of the circle = diameter/2

**Calculations:**

Let us assume the radius of the larger circle be x cm and that of the smaller circle be y cm.

ATQ, 2(x + y) = 112 ⇒ x + y = 56 ----(1)

And,

\(\pi {x^2} - \pi {y^2} = 528\)

⇒ (x + y) × (x - y) = 528 × 7/22

⇒ 56 × (x - y) = 168

⇒ x – y = 3 ----(2)

Solving (1) & (2), x = 29.5 = \(29_2^1\) cm & y = 26.5 = \(26_2^1\) cm

∴ It is a mixed fraction.