passwella.
Menu

WAEC Further Mathematics 2006 Question 16

Question 16

Statistics

The mean age of n men in a club is 50 years. Two men, aged 55 and 63, left the club and the mean age reduced by 1 year. Find the value of n.

  1. A.30
  2. B.20
  3. C.18
  4. D.14
Show the answer and explanation

Answer: B (20)

Explanation

Total age is 50n. After the two leave: (50n − 118)/(n − 2) = 49, so 50n − 118 = 49n − 98 and n = 20.