Three working women have different careers. If only one of statements 1, 2 and 3 are true, can you tell whether or not Mary is a nurse?
1. This statement is only true if statement 5 is false.
2. This statement is true if statements 4 or 5, or both 4 and 5 are true.
3. This statement is false only if both statements 6 and 1 are true.
4. Mary is a nurse
5. Karen is an artist.
6. Sarah is a photographer.