SSC CGL Official PYQQuantitative Aptitude12 Sep 2025 (Shift 1)
Q.
An annular region has outer radius 12 cm and inner radius 8 cm. What is the approximate ratio of the annular area to the whole outer circle?
A
a) 1:2
B
b) 5:9
C
c) 2:3
D
d) 3:4
Correct Answer: Option B)
Detailed Step-by-Step Explanation:
Outer area = pi * 12^2 = 144*pi. Inner area = pi * 8^2 = 64*pi. Annular area = 144*pi – 64*pi = 80*pi. Ratio = (80*pi) : (144*pi) = 80 : 144 = 5:9.