Solution to Riddle #1

For the riddle

The solution is easy yet tricky

So after drinking from the wine the prisoner can be either dead or alive. So 2 possibilities altogether.

Since the total number of prisoners available was less than 1000 so we would be busy in seaching for combinations of drinks to serve and test with the prisoners.

Though it is also possible that way but complicated.

Let’s understand a simple solution:

Let there be 10 prisoners we have chosen.

Why 10 : because we are gonna work in binary number system as there are 2 possible outcomes on each sample intake.

So 2 raised to 10 gives     ….. 1024

Slightly greater than 1000 so good for us.

Now lets number the bottles up in from 1 to 1000.

Now write the binary equivalent of each number and fit the resultant number into a 10 digit binary.
Like instead of 7-  111   – we write 0000000111

And so on for all numbers.

Now give numbers to prisoners also from 1 to 10 .

Now lets assume that these numbers correspond to there respective digits in the bottle numbers.

Now the task is done.

So now take a sample from all bottles whose 1st digit is 1 and give it to prisoner no.

And continue the procedure for all 10 digits.

Like the bottles with 1 on nth digit are taken samples and fed to prisoner number n.

Wait for the poison to act and note down the dead prisoner numbers.

Now just put 1 at positions of dead prisoners and trace the bottle up.

Like if 4,3,1 are dead – 0000001101

That is bottle no 13.

So the answer is  minimum 10 prisoners have to be used to find the poisoned wine

1. Ritz says: