Correct Answer - Option 2 : 24
Sum of ages of all the members in the group = 22 × 4 = 88 years
The ratio of ages of their ages is 7 ∶ 9 ∶ 13 ∶ 15
⇒ Let their ages be 7x, 9x, 13x and 15x
∴ 7x + 9x + 13x + 15x = 88
⇒ 44x = 88
⇒ x = 2
∴ Sum of the age of the oldest person and second youngest person of the group = 15x + 9x = 24x
⇒ Sum of the ages = 24 × 2 = 48 years
∴ Average age = 48/2 = 24
∴ The average age of the oldest person and second youngest person of the group is 24 years.