Calculating Molar solubility;?

Question

Does anyone know how to calculate molar solubility of CuS in a solution in which [H3O+] is held constant at 1.0 * 10^-1 M, the answer is 2.5 * 10^-9, but i need to see the work so i know how to do it, please

Answer 1

How about giving us the Ksp of CuS and Ka(s) for H2S?
I found some values on the net but I get a different answer.

Answer 2

For the molar solubility in water: PbCrO4 (s) --> Pb2+(aq) + CrO42-(aq) Ksp = 2.8 x 10-13 = [Pb2+][CrO42-] Ksp = 2.8 x 10-13 = [S][S] = [S]2 S = [Pb2+]= [CrO42-] = 5.3x10-7M