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JAMB Mathematics 1989 Question 9

Question 9

Mensuration of Solids

If the surface area of a sphere is increased by 44%, find the percentage increase in its diameter.

  1. A.44
  2. B.30
  3. C.22
  4. D.20
Show the answer and explanation

Answer: D (20)

Explanation

Surface area is proportional to the diameter squared. The area is multiplied by 1.44, so the diameter is multiplied by √1.44 = 1.2, a 20% increase.