SSC GD 2025 PYQ — Question 47

The correct answer is Option 2 i.e. a

Fourth proportional of a, c, bc is d

d = (c × bc) ÷ a = b × c² ÷ a

Let the fourth proportional of (bc² / a), (ad / c), c be x

x = (c × (ad / c)) ÷ (bc² / a)

x = ad ÷ (bc² / a) = ad × (a / bc²) = a²d ÷ (b c²)

Substitute d = b c² ÷ a

x = a² × (b c² / a) ÷ (b c²) = a