The Grey Labyrinth is a collection of puzzles, riddles, mind games, paradoxes and other intellectually challenging diversions. Related topics: puzzle games, logic puzzles, lateral thinking puzzles, philosophy, mind benders, brain teasers, word problems, conundrums, 3d puzzles, spatial reasoning, intelligence tests, mathematical diversions, paradoxes, physics problems, reasoning, math, science.

Ghost Post · Icarian Member

The real question for SB - based on the rules of this "game," is : Is it Monday or Tuesday? These are the two possibilities she faces upon waking.
1. If it's Monday - the "correct" answer is
1 in 2.
2. If it's Tuesday - the "correct" answer is
zero possibility that the toss was heads,
i.e. it was definitely tails
Depending on the actual day, the "correct" answer changes - but SB having no knowledge of which day it is can only assign a correct probability relative to her perspective - as follows:
We have one coin toss with three possible outcomes -
1. it's Monday and the toss is heads
2. it's Monday and the toss is tails
3. it's Tuesday and the toss is tails
The correct answer RELATIVE TO SB's PERSPECTIVE is 1 in 3.

Apparently it's true - everything is RELATIVE!