ECZ 2019 · GCE Paper 1 — Similarity and Congruency
The ratio of the volumes of two similar solids is 64 : 27. The surface area of the smaller solid is 180 cm². What is the surface area of the bigger solid?
- A. 405 cm²
- B. 240 cm²
- C. 426⅔ cm²
- D. 320 cm²
Verified working — step 1
Volumes 64 : 27 give a length ratio of ∛64 : ∛27 = 4 : 3. Areas go as the square of lengths: 16 : 9. So the bigger surface area = 180 × 169= …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.
Have a different question?
Search it — if it is from a past paper or a school mock, chances are we have it worked out, or one that uses the same method.
Search any past-paper question