Questions tagged [probability]
A mathematical puzzle whose essential nature involves randomness. Use with [mathematics]
428
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4
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Revealing the least helpful of three numbers
(This is a follow-up to Guessing whether the revealed number is higher.)
They're at it again. This time Andrew is secretly shown three real numbers, all independently, randomly, uniformly chosen from ...
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Guessing whether the revealed number is higher
Consider the following game:
Two real numbers are independently, randomly, uniformly chosen from the interval [0, 1].
Andrew is secretly shown the two numbers. He must choose one of the numbers and ...
- 1,704
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Unpaired socks in my lap
Today in my laundry basket I had 10 distinct pairs of socks. I repeatedly take a sock randomly from my basket. If it matches a sock in my lap, I pair both up and put them aside, otherwise I put it on ...
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The HH vs HT question
My puzzle is based on this tweet (image):
Flip a fair coin 100 times—it gives a sequence of heads (H) and tails (T). For each HH in the sequence of flips, Alice gets a point; for each HT, Bob does, ...
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Diamond Rush: Back to... um
It is summer in the Pse School Of Logicians, and everyone studying there is dying for a break (they absolutely hate school, and can do anything to get out of it). And because the teachers there are ...
- 1,120
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Winning chance in coins game with fixing
A player plays the following solitaire game. The game consists of as many rounds as are needed to produce a result. They have 20 fair coins, which may in any round be live or fixed; each coin starts ...
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The Alien Snails Experiment
Fictional Background Story (The Experiment):
Two extremely fast and intelligent alien snails are randomly placed on two different points on an infinite plane, as an experiment by the cruel ruler of ...
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Picasso at the art school [closed]
Picasso is preparing for his fine art exam. At the exam he will be shown exactly (a replica of) one of the following four paintings chosen uniformly at random:
Mona Lisa
The Last Supper
The Starry ...
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Impossible Minesweeper?
I was playing the game Minesweeper earlier today and came across the following situation:
(Look at the bottom-middle section of the gameboard.)
It seems to me that either of the two diagonal pathways ...
- 1,112
7
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2
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Does this random sequence contain the number 1?
Randomly choose a number from 1 to 3 and call it $a_1$;
Randomly choose a number from 1 to 3$a_1$ and call it $a_2$;
Randomly choose a number from 1 to 3$a_2$ and call it $a_3$;
$\cdots$
Repeat this ...
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How many pencils are there? [closed]
Four pencils are chosen (without replacement) from a pencil case, two of which are blunt. The probability that both blunt pencils are chosen is twice the probability that neither is chosen. How many ...
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The Monty Hall loot box
Everyone sufficiently competent in probability knows that in The Monty Hall problem as most commonly presented, switching doors wins you the car $\frac23$ of the time. I have come up with this ...
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What is the probability that your life will have lasted for 100 years once you die?
You are in a world where exactly 90% of all people live for exactly 3 years, and exactly 10% of all people live for exactly 100 years.
Aside from what I mention here there is no information that can ...
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Button multi arm bandit problem
Let's say you have the following buttons to press, labeled a - j, that would earn you the following amounts of money:
a: \$6
b: \$9
c: \$15
d: \$26
e: \$45
f: \$78
g: \$136
h: \$416
i: \$728
j: \$...
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0
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What is the probability I can't bike despite good weather? [closed]
I am trying to solve this puzzle:
I have a total of two bikes that I keep at work or at home. I always bike to and from my work unless it rains, in which case I take a taxi (and don't bring my bike). ...
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