If am, bm, and cm satisfy the inequalities 0 < bm < cm < am , for all m, what can we say about the
[infinity][infinity]
(a)σam(b)σbm
m=1m=1
series if we know that the series
[infinity]
(c)σcm
m=1
is divergent but know nothing else about am and bm?
1. (a) diverges , (b) diverges
2. (a) diverge, (b) converges
3. (a) converges, (b) need not converge
4. (a) converges, (b) diverges
5. (a) need not diverge. {b) diverges
6. (a) diverges, (b) need not diverge