This gives a solution using 60 servants for 1024 wines.Represent the wines using 10-bit binary numbers. Name the bits from A-J. Group the adjacent bits.
AB--CD--EF--GH--IJ What is the value of AB for poisons? Give follg sets of wines to 4 different people.
AB=00; AB=01; AB=10; AB=11 If only one of them die, AB is completely resolved! If not, we get partial information. Do similar tests on remaining 4 groups.
00--0(0|1)--11--(0|1)1--1(1|00|1) Consider CD & GH. If we know if set DG=00 died, we can link them. Since we dont know which test would be required, we run all 4-tests:
CG=00; CH=00; DG=00; DH=00 Similarly for GH and JK. If GJ=00 didnt die, the poisons will be:
00--00--11--01--11 00--01--11--11--10 Total # of tests/people needed: 5*4 + C(5,2)*4 = 60
PS: If you use groups of 3 (rather than 2), it doesn't improve. If you use groups of 4 or more, it worsens.