Question

Watson, I have uncovered the following facts: If Mrs Smith is lying then Moriarty has not escaped. Either Moriarty is dead or he is really Jones. If Moriarty is really Jones then he has escaped. • I am convinced Mrs Smith is lying. Good Lord Holmes," replied Dr Watson, "what can you make of all this?" "Elementary my dear Watson, Moriarty is dead!" Is Holmes correct? Justify your answer

Answer 1

Answer:

Yes, Holmes is correct.

Step-by-step explanation:

Let's separate each statement of Holmes: (they are all true)

1. If Mrs. Smith is lying then Moriarty has not escaped.  
2. Either Moriarty is dead or he is really Jones.  
3. If Moriarty is really Jones then he has escaped.  
4. I am convinced Mrs. Smith is lying.

If we start with the last one, we know that Mrs. Smith is lying. That takes us to the first one, Mrs. Smith IS lying, so Moriarty has not escaped.

If we look the second one, either Moriarty is dead or he is really Jones.

If he is really Jones, that takes us to the third statement that says that Moriarty has escaped. But we know from the first statement that he hasn't escaped, so he can't be Jones.

So, going back to the second statement, Moriarty is dead.