math problem

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gutuami
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requires a quick answer.

A bat and a ball cost $1.10 in total. The bat costs $1 more than the ball. How much does the ball cost?
LinusP
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$0.05

:D
marko236
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Trying to work this out for 10 minutes, doing my head in so i'll go for dumb answer 10c
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gutuami
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marko236 wrote:Trying to work this out for 10 minutes, doing my head in so i'll go for dumb answer 10c
:) in that case the bat should cost only 90c more than the ball
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gazuty
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Location: Green land :)

gutuami wrote:requires a quick answer.

A bat and a ball cost $1.10 in total. The bat costs $1 more than the ball. How much does the ball cost?
Alway reduce every problem to an equation. That's what I do.


Bat = x
Ball = y

X + y = 1.1

X= y + 1

Y + y + 1 = 1.1

2y = .1

Y = 0.05
marko236
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gazuty wrote:
gutuami wrote:requires a quick answer.

A bat and a ball cost $1.10 in total. The bat costs $1 more than the ball. How much does the ball cost?
Alway reduce every problem to an equation. That's what I do.


Bat = x
Ball = y

X + y = 1.1

X= y + 1

Y + y + 1 = 1.1

2y = .1

Y = 0.05
When i was at school i was ok doing equations, it's been along time 20 years! so a bit rusty, handy thing to know and must help with trading ideas.

Good post
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gutuami
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Behavioral economist Daniel Kahneman explains why most people get this wrong:

A number came to your mind. The number, of course, is 10: 10¢. The distinctive mark of this easy puzzle is that it evokes an answer that is intuitive, appealing, and wrong. It is safe to assume that the intuitive answer also came to the mind of those who ended up with the correct number—they somehow managed to resist the intuition.

Many thousands of university students have answered the bat-and-ball puzzle, and the results are shocking. More than 50% of students at Harvard, MIT, and Princeton gave the intuitive—incorrect—answer. At less selective universities, the rate of demonstrable failure to check was in excess of 80%.



Read more: http://www.businessinsider.com/question ... z3V9oV2jfE
marko236
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I think the question pushes you into the wrong answer, i know the answer wasn't 10c, but i kept reading the question and it pushed me away from thinking properly, it kind of plays with your thinking. I think well over 95% of the worlds population would get this wrong.

On second thought, alot of people would know that it wasn't 10c so would put a guess off less than 10c, so my above estimate of 95% would probs be wrong as some would guess right.
Wyndon
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[quote="gazuty"]

Alway reduce every problem to an equation. That's what I do.


/quote]

Sorry Gazuty, can't resist the opportunity to remind you that when even when you got the correct equation, your gut feeling still failed to recognise the significance of the result. :)

viewtopic.php?f=36&t=7631
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gazuty
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Location: Green land :)

Wyndon wrote:
gazuty wrote:
Alway reduce every problem to an equation. That's what I do.


/quote]

Sorry Gazuty, can't resist the opportunity to remind you that when even when you got the correct equation, your gut feeling still failed to recognise the significance of the result. :)

viewtopic.php?f=36&t=7631
Agree.

I reduce everything to an equation and even then my limbic brain interferes.
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mklim_irlpl
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Doesn't it cost anything from 0.01 to 0.1? :D
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gutuami
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You have Albert, Bernard and Cheryl. Cheryl says "my birthday is one of these ten dates"

May 15 May 16 May 19
June 17 June 18
July 14 July 16
August 14 August 15 August 17

She gives Albert the month of her birthday. And Bernard the number.

Then the following conversation occurs:

1) Albert: I don’t know when the birthday is, but I know Bernard doesn’t know too.
2) Bernard: At first I don’t know when the birthday is, but now I know.
3) Albert: Then I know the birthday too.

From that information, work out Cheryl's birthday.
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gutuami
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gutuami wrote:You have Albert, Bernard and Cheryl. Cheryl says "my birthday is one of these ten dates"

May 15 May 16 May 19
June 17 June 18
July 14 July 16
August 14 August 15 August 17

She gives Albert the month of her birthday. And Bernard the number.

Then the following conversation occurs:

1) Albert: I don’t know when the birthday is, but I know Bernard doesn’t know too.
2) Bernard: At first I don’t know when the birthday is, but now I know.
3) Albert: Then I know the birthday too.

From that information, work out Cheryl's birthday.
solution: https://www.youtube.com/watch?v=emiMj8cCL5E
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marksmeets302
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Awesome!
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marksmeets302
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problem.gif
You have to walk from point A to point B 10 times, blindfolded. Every time before you start walking, a fair coin is tossed, and if it comes out heads, a wall in the middle is present (situation 2 in the picture), while if it comes out tails it is not (situation 1 in the picture). As you are blindfolded, you do not know if the wall is present or not.
Even though you are blindfolded, you can move in perfectly straight lines towards any point you choose. Can you give a prescription how to walk from A to B so that the total distance you cover is as small as possible?
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