ECZ 2023 · O-Level Paper 1 — Variation
a varies jointly as b and the square root of c, and a = 21 when b = 5 and c = 36. Find the value of c when a = 70 and b = 25.
- A. 25
- B. 16
- C. 4
- D. 64
Verified working — step 1
Two moves: pin down k from the triple you are given, then solve backwards - c hides under a square root, so dig out √c first and square it at the very end.The full step-by-step working and final answer, plus the video lesson for this topic, are included with Premium — checked against ECZ marking standards.
Original examination question © Examinations Council of Zambia. Worked solution and commentary © G12 Titan — not to be reproduced without permission.
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