ECZ 2025 · O-Level Paper 1 — Sets
If P={1,3,5,7},P∪Q={1,2,3,4,5,6,7} and P∩Q={5,7}, list Q.
- A. {1,2,4,5,6}
- B. {2,3,4,6,7}
- C. {2,4,5,6,7}
- D. {1,2,4,6,7}
Verified working — step 1
The intersection P∩Q={5,7} tells us that 5 and 7 must be in Q. The union P∪Q={1,2,3,4,5,6,7} contains 2, 4, and 6, which are not in P, so they must come from Q. Therefore,The full step-by-step working and final answer 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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