Concept:The puzzle is a logic deduction problem: using the responses of the three logisticians to infer the colors of tickets on Newton's forehead given the total counts and the fact that each sees others' tickets but not his own.
Explanation:Let
g,n,e be the number of blue tickets on Galelio, Newton, Einstein respectively (each can be
0,1,2). Total blues =
4, yellows =
4. The foreheads use
6 tickets, the pocket
2, so
g+n+e must be
2,
3, or
4.
By simulating the reasoning steps (G's first "No", N's first "No", E's "No", G's second "No", N's final "Yes") and eliminating all inconsistent states, the only surviving states all have
n=1 (one blue, one yellow).
Thus Newton's tickets consist of one blue and one yellow.
Answer:The colours are one blue and one yellow, which is not listed as "both blue" or "both yellow", and the answer is determined. Therefore option D is correct.