ECZ 2025 · GCE Paper 1 — Approximations
If 12.5 litres of water was poured out of a container containing 20 litres of water, find the relative error of the volume of water that remained in the container.
- A. 11150
- B. 1150
- C. 0.625
- D. 0.375
Verified working — step 1
The remaining volume is 20 − 12.5 = 7.5 litres. Each measurement carries half its unit of precision: 20 litres (nearest litre) has absolute error 0.5 and 12.5 litres (one decimal place) has absolute error 0.05. Errors add when quantities are subtracted: 0.5 + 0.05 = 0.55. Relative error = 0.55 ÷ 7.5 = …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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