Question

The average age of nine member in steam is 24 years. When a new member joins the team, the average age of the team become 27 years

Answer 1

Average Age of 9 members = (sum of ages of 9 members)/9

⇒24 = sum of ages of 9 members/9

⇒sum of ages of 9 members = 9 × 24 = 216

let age of new member = x

so sum of ages of 10 members = sum of ages of 9 members + x = 216 + x

And Average of 10 members = (sum of ages of 10 members) / 10

⇒ 27 = (216+x) / 10         [ since given average age of 10 member team = 27 ]

⇒ 270 = 216 + x

⇒ x = 270 - 216 = 54

Hence age of new member is 54 years