The ages of 5 people are in the ratio 2 : 3 : 4 : 10 : 11. If their average age is 18 years, find the age of the eldest person.

Question: The ages of 5 people are in the ratio 2 : 3 : 4 : 10 : 11. If their average age is 18 years, find the age of the eldest person.

Solution:
Given that,
The ages of 5 people are in the ratio 2 : 3 : 4 : 10 : 11
And average age = 18 years

Let the common ratio multiplier = x
So their ages are: 2x, 3x, 4x, 10x, 11x

∴ Total age = 2x + 3x + 4x + 10x + 11x = 30x

Now,
30x/5 = 18
⇒ 30x = 90
⇒ x = 90/30
∴ x = 3

Age of the eldest person = 11x = 11 × 3 = 33 years

So, the eldest person is 33 years old.