Conductor with a charge problem

[STP]

Hey everyone, first post and having an issue thinking about a simple problem. I'm into chemistry so I struggle to get all of these physics ideas down correctly.

The problem is about a conductor with a neutral surface. The conductor has a cavity with a point charge of +P inside of it. A charged rod transfer -q to the conductor.

My issue is finding the charge on the inner wall of the conductor's cavity. My book doesn't describe a transfer of this sort and just says the inner wall of the cavity has to cancel out the point charge.

Thanks

 

[Shooting Star]

Surround the cavity by a Gaussian surface S lying inside the conductor. Inside a conductor, the field is always zero. The closed surface integral over S, integral E.da = 0, since E = 0 at every point. What do you think the induced charge on the cavity wall should be using Gauss’ law?