# Math Help - the mean

1. ## the mean

Hi, this is my question:

The mean age of 5 friends is 36.
Another person joins the group and the mean age drops to 35.
how old is the 6th person?

im not sure how to work this out so could someone show me please?

2. Originally Posted by andyboy179
Hi, this is my question:

The mean age of 5 friends is 36.
Another person joins the group and the mean age drops to 35.
how old is the 6th person?

im not sure how to work this out so could someone show me please?
If you denote by 'S' the sum of ages of the 5 friends and by 'a' the age of 6th person, you arrive to these two equations:
S/5=36
(S+a)/6=35

Can you solve them?