Question

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

Answer 1

n=20

Sum of age of men = 50n

when 2 left,

(50n-55-63)/n-2=50-1

50n-55-63=49n-98

50n-55=49n-35

50n-49n=-35+55

n=20