Help on finding which anion a solution contains

Can someone please help me?! Greatly appreciated!

1. A solution which contains only one of the following anions: I-, SO4 2-, or OH- is tested with the various reagents and the following results are obtained:
REAGENT RESULTS
0.2M AgNO3 precipitate
0.2M Fe(NO3)2 no precipitate
0.2M Sr(NO3)2 no precipitate
Which anion does the solution contain? _______

2. A solution which contains only one of the following anions: OH-, SO4 2-, or CO3 2- is tested with the various reagents and the following results are obtained:
REAGENT RESULTS
0.2M AgNO3 precipitate
0.2M Fe(NO3)2 precipitate
0.2M Sr(NO3)2 no precipitate
Which anion does the solution contain? _______

1. is SO4 2-
2. CO3 2-