Answer: Option A
Answer: (a)Reduction in total age of 45 persons = 45 × $1/9$ Age of the new person = 60 – 45 × $1/9$ = 55 years Aliter : Using Rule 23, ( If in a group, one member is replaced by a new member, then, Age of new member = ( age of replaced member) ± xn where, x = increase (+) or decrease (–) in average n = Number of members. )Age of new corner = Age of replaced member – xn = 60 – 45 × $1/9$ = 60 – 5 = 55 years