Math Help - Factor groups question

Basically I know how to do the first part, it's just the multiplication table giving me problems. I know the headings for the table should be H, (1,2)H, (1,3)H, (2,3)H, (1,2,3)H, (1,3,2)H but I don't know anymore.

Multiplication in factor groups is easy. It is defined as
.

For example Let . Since G is abelian, H is normal in G.

Consider two cosets of , .

Now in your example, we take . since