The sultan asked the vizier:
“The tests so far for finding my successor are way too easy. We’ve got to make them harder. There are still dozens of candidates left.”
“This one is definitely more difficult. First, they got to swim”
“So they had in the previous test,” the sultan grumbled.
“If they come up to breath, there heads will be shot off,” the vizier explained.
The sultan nodded approval.
“There are four doors.”
“So had the previous test”
“But now there are two labels on every door. So they’ve got to think twice as fast!”
The first candidate look at the four doors.
“Again only one door hides a treasure,” the vizier explained. “There is a shark behind each of the other three.”
The candidate looked at the labels. He could see that there were two labels on each door, but he couldn’t read them.
“And how many labels are true? Or how many doors have true labels?”
“That is a very good question”, the sultan smiled. “As a matter of fact, knowing which door hides the treasure, it was impossible to decide upon the number of true labels. So how you should decide the number of true labels while you don’t know which door hides the treasure, is beyond me.”
Which door should the candidate open?
New puzzles are published at least once a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars. You can check your solution here.