Question

The average age of a group of 8person was 14 years.A person with age 28 years left the group and a new person with age 16 years joined the group.Find the new average age of the group? a)13years. b)14years c)15.5years. d)12.5years​

Answer 1

Answer:

12.5 years

Step-by-step explanation:

Total age of the group = 14×8 = 112

$total \: age \: of \: a \: group \: = \: the \: number \: of \: persons \: in \: the \: group \times average \: age \: of \: the \: group$

Total age of the group after leaving the person of the age 28 years = 112-28 = 84

Total age of the group after joining the new person = 84+16 = 100 years

Hence, average age of the new group = 100/8-1+1 = 12.5 years.

$average \: age \: of \: a \: group \: = \: \frac{total \: age \: of \: the \: group}{total \: number \: of \: persons \: in \: the \: group}$