Einstein's puzzle: Can you sovle it?

Correct / Incorrect / Incorrect

Incorrect / Correct / Incorrect

Incorrect / Incorrect / Correct

Those are the only possible initial conditions. Obviously you don't know which one you are given, but those are the only one's that are possible in a 3 door game.

 

If you dont believe Alphe, do a search on google
for the Monty Hall problem.
Lots of explainations out there.

The posted solutions agree wtih Alphe.

peace

axeman

 

The a priori probability that the prize is behind door X, P(X) = 1/3

The probability that Monty Hall opens door B if the prize were behind A,
P(Monty opens B|A) = 1/2

The probability that Monty Hall opens door B if the prize were behind B,
P(Monty opens B|B) = 0

The probability that Monty Hall opens door B if the prize were behind C,
P(Monty opens B|C) = 1

The probability that Month Hall opens door B is then
p(Monty opens B) = p(A)*p(M.o. B|A) + p(B)*p(M.o. B|B) + p(C)*p(M.o. B|C)
= 1/6 + 0 + 1/3 = 1/2

Then, by Bayes' Theorem,

P(A|Monty opens B) = p(A)*p(Monty opens B|A)/p(Monty opens B)
= (1/6)/(1/2)
= 1/3
and
P(C|Monty opens B) = p(C)*p(Monty opens B|C)/p(Monty opens B)
= (1/3)/(1/2)
= 2/3

In other words, the probability that the prize is behind door C is higher when Monty opens door B, and you SHOULD switch!

 

A customer at a 7-11 store selected four items to buy, and was told that the cost was $7.11. He was curious that the cost was the same as the store name, so he enquired as to how the figure was derived.

The clerk said that he had simply multiplied the prices of the four individual items. The customer protested that the four prices should have been ADDED, not MULTIPLIED. The clerk said that that was OK with him, but, the result was still the same: exactly $7.11.

What were the four prices?

 

During a recent Formula 1 race meeting, Sterling managed to complete a lap with an average speed of 150 mph. He managed to complete the first two fifths of the lap at a speed of 123 mph and the second two fifths of the lap at a speed of 164 mph. At what speed was the final one fifth of the lap covered - the answer is not 176 mph?

 

Find an word which is singular, add an 's' and it becomes plural, and add another 's' it becomes singular again?

 

def,

Thank you. I stand corrected. That was a great thread, and I learned much by following it.

 

Prince

Princes

Princess

 

$3.16, $1.50, $1.20, and $1.25

 

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