Question

The mean age of 5 people in a room is 40 years. A person enters the room. The mean age is now 36. What is the age of the person who entered the room?

Answer 1

`\boxed{\sf \ \ \ age = 16 \ \ \ }`

Explanation:

Hello,

as the mean age of 5 people is 40

it means that the sum of the 5 ages is 40*5=200

now a person enters the room, let's note x his age

the new mean is

`(200+x)/(6)=36`

`<=>200+x=6*36=216\\<=> x = 216-200=16\\`

So the age of the new person is 16

hope this helps