predict the actual precipitates which form (if such is the case) when the following solutions are mixed.
a) silver sulphate and barium chloride
b) ammonium iodine and potassium phosphate''
c) lead(II) acetate and rubidium bromide
Here is a simplified list of the solubility rules. Note in the first one that BaSO4 is insoluble. The others are done the same way. You should memorize this table.
http://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html