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JAMB Mathematics 1993 Question 46

Question 46

Measures of Central Tendency

The mean of the ages of ten secondary school pupils is 16 but when the age of their teacher is added to it, the mean becomes 19. Find the age of the teacher.

  1. A.27
  2. B.35
  3. C.38
  4. D.49
Show the answer and explanation

Answer: D (49)

Explanation

The ten pupils total 10 × 16 = 160 years. With the teacher, 11 people total 11 × 19 = 209 years, so the teacher is 209 − 160 = 49.