Carl sent in his solution. He filled in the table by putting a X if he knew it definitely wasn't the answer, and an O if he knew it definitely was.

Cherri is the oldest, so she must be 8. So we can fill in the table like this (because she can't be any other age, and nobody else can be 8).

5 6 7 8
Cherri X X X O
Paul X
Saxon X
Mel X

Since Saxon's age is an even number, he must be 6, so we can fill in the table like this.

5 6 7 8
Cherri X X X O
Paul X X
Saxon X O X X
Mel X X

Now Mel's age is half of Cherri and Saxon's ages added together, so Mel's age is half of 8+6=14, so Mel is 7 and Paul is 5. If we wanted to, we could fill in the table to show the answer:

5 6 7 8
Cherri X X X O
Paul O X X X
Saxon X O X X
Mel X X O X