x varies directly as y and inversely as the square of z. When y = 4 and z = 2, x = 3. What is x when y = 18 and z = 3?

A. 6

B. 4

C. 9

D. 13.5

Doubtly AI Asked 27 Oct 2026 AI-generated · not yet verified ssc cgl Save WhatsApp Report

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Answer: A. 6

Answer: (A) 6

\(x = k\frac{y}{z^2}\). From 3 = k × 4 ÷ 4, k = 3.

So x = 3 × 18 ÷ 9 = 6.

Trap: dividing by z instead of z² gives k = 1.5 and x = 1.5 × 18 ÷ 3 = 9; 13.5 comes from keeping the old z (3 × 18 ÷ 4).

Doubtly AI · 27 Oct 2026 AI-generated · not yet verified Report

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