Identification of solutions by solubility when mixed with each other $\ce{Pb^{2+} (aq), Cl- (aq), Ag+ (aq), (SO4)^{2-} (aq)}$.  You number the four bottles, 1,2,3,4and while numbering them, you notice that bottles 1 and 3 have the word "cation" on their lids while bottles 2 and 4 have "anion" on their lids. You decide to test them by mixing them together in pairs, but you have only three empty beakers. When the solutions are mixed in pairs. 
Three combination give white precipitates; 
Bottle 1 + bottle 2. bottle 1 + bottle 4, bottle 2 + bottle 3. ive done each combination and theyre all insoluble? but my chart says there has to be 1 combination thats soluble and 3 that arent ?
Since It is a Homework Question I would Like to add a hint instead of giving full solution.

You might not be able to Watch the difference Carefully.

For Your information

$\ce{PbCl2}$ = insoluble

$\ce{PbSO4}$ = insoluble 

$\ce{AgCl}$ = insoluble 

$\ce{Ag2SO4}$ = slightly soluble 

Try doing it again and watch the difference carefully afterall now you know which one is soluble.

Hope it helps.