Edit: Forgot to type "stumped" at the end of the title 1. The problem statement, all variables and given/known data Instead of typing it out, a link to a scanned document of the problem is here: http://imgur.com/Be3jSLp. 2. Relevant equations The equations to use are stated in the problem here: http://imgur.com/Be3jSLp 3. The attempt at a solution For 3.a: Wouldn't you have to draw a gaussian sphere around the outer edge of the sphere, which would yield an enclosed charge of Q_o? Then after that, wouldn't you draw another one inside the conducting shell, resulting in an enclosed charge of zero? Therefore, wouldn't the charge at the center be -Q_o? For 3.b: Using the equation given, I don't know exactly how to integrate the equation after you substitute in the E value given in the beginning of the problem. Any advice?