Wikipedia:Reference desk/Archives/Mathematics/2019 December 31

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December 31

Last puzzle of 2019

“I am a time traveller!” said the time traveller. “Bullshit!” said I. “I will prove it to you. Get a fair dice. Color the side 1,2 and 3 as red. Color the sides 4 and 5 as green. And finally colour the side 6 as blue.” I did as the traveller asked.

“Now I will write down the color which you will roll” said the traveller and wrote down something on a piece of card which was placed face down so I could not see what was written.

“Roll the die!” the time traveller demanded. I did. “now watch this!” the traveller said and turn over the card.

The card showed a word correctly described the color of the side of the dice which I rolled.

Question: Assuming the time traveller is a Fraud, what is the probability of writing down the correct result on the card before I rolled the dice? 49.177.234.140 (talk) 08:28, 31 December 2019 (UTC)

Please do your own homework.

Welcome to Wikipedia. Your question appears to be a homework question. I apologize if this is a misinterpretation, but it is our aim here not to do people's homework for them, but to merely aid them in doing it themselves. Letting someone else do your homework does not help you learn nearly as much as doing it yourself. Please attempt to solve the problem or answer the question yourself first. If you need help with a specific part of your homework, feel free to tell us where you are stuck and ask for help. If you need help grasping the concept of a problem, by all means let us know. –Deacon Vorbis (carbon • videos) 14:12, 31 December 2019 (UTC)

Not quite Maths (and may only work in English), but how about certain? 6 — Preceding unsigned comment added by 213.31.114.2 (talk • contribs) 10:34, 1 January 2020 (UTC)

The answer depends on how the "time traveller" chooses the word that she writes on the card. If she makes a random choice between "red", "green" or "blue" then the probability of writing down the correct colour is 1/3. However, if she always writes "red" then the probability that she is correct is 1/2. And if she always writes "blue" then the probability that she is correct is only 1/6. Gandalf61 (talk) 14:34, 3 January 2020 (UTC)