One fellow (
A) lies only on Mondays, Tuesdays, and Wednesdays, and tells the truth on other days, and his friend (
B) lies on Thursdays, Fridays, and Saturdays, and tells the truth on other days.
At noon, they have the following conversation:
A: I lie on Saturdays.
B: I will lie tomorrow.
A: I lie on Sundays.
On which day of the week does this conversation take place?
Adapted from Crux Mathematicorum.
(In reply to
Puzzle Answer by K Sengupta)
WLOG, we can denote the day the conversation takes place as "today".
Since A lies only on Mondays, Tuesdays and Wednesday, it follows that his first statement is false.
Accordingly, today is Monday, Tuesday, or Wednesday. ....,,,,,(i)
Now, B always tells the truth on Thursdays, Fridays, and Saturdays. So, in accordance with his (true) statement - today must be Wednesday, Thursday. or, Friday. ............(ii)
The only d.o.w. common between (i) and (ii) is Wednesday and, accordingly, today must be Wednesday . A"s second statement, although consistent with the given conditions is superfluous.
Consequently , this conversation takes place on a Wednesday.
Explanation for Puzzle Answer
