Premise: I am 18 years old and face a serious problem.

Hypothesis: I am eighteen years old and I have never suffered through any problems.
Answer: no

Premise: You have been with your mistress many years, is it not so?

Hypothesis: His mistress was prettier than his wife.
Answer: it is not possible to tell

Premise: the trouble is they think they can buy it for a thousand dollars or less

Hypothesis: They can buy it for only one hundred dollars.
Answer: no

Premise: I totally agree (if there is a drug link), get them out.

Hypothesis: I agree; those people should not be in jail for a marijuana charge.
Answer: it is not possible to tell