(a)

Suppose that and  are series with positive terms.

is a divergent series.

Therefore by the comparison Test part(ii) if for all n,we can say is a divergent.

(b)

Suppose that and  are series with positive terms.

And is a divergent series.

By the Comparison Test, we cannot say anything about convergence of .

Because is a divergent series. and If  for all n, then comparision  test doesnot give any result.

(a)  Divergent.

(b)  No conclusion.