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WAEC Mathematics 2015 Question 13

Question 13

Mensuration of Solids

The volume of a cone of height 3 cm is 38½ cm3. Find the radius of its base. [Take π = 22/7]

  1. A.3.0 cm
  2. B.3.5 cm
  3. C.4.0 cm
  4. D.4.5 cm
Show the answer and explanation

Answer: B (3.5 cm)

Explanation

⅓ × 22/7 × r² × 3 = 38.5 gives r² = 12.25, so r = 3.5 cm.