Heeellllp!!!

[Guest]

I am totally lost. I do not even know where to start!!!

The Sum of the ages of Al and Billis 25; The sum of the ages of Al and Carl is 20; The sum of the ages of Bill amd Carl is 31.

Who is the oldest of the three and how old is he?

 

[Denis]

I am totally lost. I do not even know where to start!!!
The Sum of the ages of Al and Billis 25; The sum of the ages of Al and Carl is 20; The sum of the ages of Bill amd Carl is 31.
Who is the oldest of the three and how old is he?

You start like this:
a=Al, b=Bill, c=Carl :!:

The sum of the ages of Al and Bill is 25 : a + b = 25
The sum of the ages of Al and Carl is 20: a + c = 20
The sum of the ages of Bill amd Carl is 31: b + c = 31

If you are still totally lost, then you need a talk with your teacher...