Brain Teasers
Eight People
In a mathematics contest, A, B, C, D, E, F, G and H got the top eight places. The teacher asked them to guess who got first.
A said: "Either F or H is first."
B said: "I'm first."
C said: "G is first."
D said: "B is not first."
E said: "A is wrong."
F said: "Neither I nor H is the first."
G said: "C is not first."
H said: "I agree with A."
The teacher told them that exactly three of them guessed correctly. Then, who got first?
A said: "Either F or H is first."
B said: "I'm first."
C said: "G is first."
D said: "B is not first."
E said: "A is wrong."
F said: "Neither I nor H is the first."
G said: "C is not first."
H said: "I agree with A."
The teacher told them that exactly three of them guessed correctly. Then, who got first?
Hint
It's OK to use trial and error, however, there might be better methods.Answer
Since B and D contradict each other, exactly one of them must be true.Since A and H agree with each other while E and F are against them, exactly two of these four must be true.
Therefore, neither C nor G guessed correctly. Since G guessed that C is not first, C must be first.
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Comments
so der 4 it would be d,e,and f... i gueesed A D and H
I agree... A, D, and H could have been guessing correctly, with the others being incorrect. Therefore, H was first.
Faulty teaser!
Faulty teaser!
If H is first then
A, D, G, and H are correct. That makes four. right?
A, D, G, and H are correct. That makes four. right?
same
psycho!!
i guessed H would be the first!
i guessed H would be the first!
It can be either C or I. They both have equivalent cases: nobody picks them and exactly one person says it wasn't them.
This teaser is flawed and should not have been approved.
This teaser is flawed and should not have been approved.
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