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WAEC Mathematics 2019 Question 22

Question 22

Mensuration of Solids

The total surface area of a solid cylinder 165 cm2. If the base diameter is 7 cm, calculate its height. [Take π = 22/7]

  1. A.7.5 cm
  2. B.4.5 cm
  3. C.4.0 cm
  4. D.2.0 cm
Show the answer and explanation

Answer: C (4.0 cm)

Explanation

Total surface area = 2πr2 + 2πrh with r = 3.5: 165 = 77 + 22h, so 22h = 88 and h = 4 cm.