Wednesday, November 20, 2019

Drink puzzle

First, we divide the 1000 bottles into two groups (Group- A and  Group_B), each has 500 bottles of wine. Then get one dip from each bottle of Group A, and let the first rat drink. If the rat die, then the poison bottle should be in Group-A or will be in the Group-B.

Follow the logical, we use the same strategy for the rest bottles until we find the one. (see the table)
each time, we divide the total bottle into two groups, then can determine one of the group has poison.
In this way, we use 10 rats can find poison wine.

No. run
Total bottles of wine
The bottles in the poison group
1
1000
500
2
500
250
3
250
125
4
125
(62 or 63)
5
63
(31 or 32)
6
32
16
7
16
8
8
8
4
9
4
2
10
2
1

The question needs 10 rats because of 2^9 <1000<2^10.

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