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WAEC Mathematics 2025 Question 5

Question 5

Mensuration of Solids

Two ball bearings have volumes 1.6 cm3 and 5.4 cm3. Find the ratio of their surface areas.

  1. A.4 : 9
  2. B.2 : 3
  3. C.3 : 8
  4. D.5 : 12
Show the answer and explanation

Answer: A (4 : 9)

Explanation

Volumes are in the ratio 16 : 54 = 8 : 27 = 2³ : 3³, so the radii are 2 : 3 and the surface areas 2² : 3² = 4 : 9.