The Confidence Test- The Science of Irrationality

[Chris-PA]

Two equations, two unknowns:

Bat + Ball = $1.10
Bat = Ball + $1.00

Solve for Ball:

Bat + Bat – $1.00 = $1.10
2 X Bat = $0.10
Bat = $0.05

Better grammar would have helped in the original problem: "A ball and bat both cost $1.10" should have been something like: "The total cost of a ball and bat is $1.10"

 

[WidowMaker]

Two equations, two unknowns:

Bat + Ball = $1.10
Bat = Ball + $1.00

Solve for Ball:

Bat + Bat – $1.00 = $1.10
2 X Bat = $0.10
Bat = $0.05

Better grammar would have helped in the original problem: "A ball and bat both cost $1.10" should have been something like: "The total cost of a ball and bat is $1.10"

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The phrasing is part of the test...

 

[Chris-PA]

===

The phrasing is part of the test...

It certainly is, but I don't know if was intended to be. Intentionally making the information provided confusing or unclear only makes the results less convincing. The idea was that people often use their intuition and jump to conclusions that they are convinced are obviously correct, and are not - not that you can befuddle people with confusingly stated problems. I also feel that the opposite is true - people who try to live only by analysis and ignore their intuition are ignoring valuable insight.

 

[Blazin]

Half a cord? :rolleyes2:

 

[Coldfront]

By the way it was worded I have to say 10 cents. But if it meant they both separately cost $1.10 then the ball cost a $1.10

 

[Fyrebug]

Half a cord? :rolleyes2:

Would that be a 'face' cord?

 

[Hedgerow]

It certainly is, but I don't know if was intended to be. Intentionally making the information provided confusing or unclear only makes the results less convincing. The idea was that people often use their intuition and jump to conclusions that they are convinced are obviously correct, and are not - not that you can befuddle people with confusingly stated problems. I also feel that the opposite is true - people who try to live only by analysis and ignore their intuition are ignoring valuable insight.

My intuition is still a little bit hazy after drinking $1480.00 worth of Fyrebug's beer... I don't even remember what the hell happened to the bat...
:tire:

 

[Blazin]

Would that be a 'face' cord?

More like a rick

 

[russhd1997]

So this thread wont get moved I'll ask a Firewood, Heating and Wood Burning Equipment question. Is the bat made out of ash or maple?

It is made of Chinese plastic. Real American wood is too expensive.otstir:

 

[D&B Mack]

More like a rick

Or, a pick-up truck load.

 

[D&B Mack]

Explain that for me

$1.10 combined.

$1.10 = Ball + Bat

&

Bat = Ball + $1.00

Therefore,

$1.10 = Ball + (Ball + $1.00) = Ball + Ball + $1.00 = 2 x Ball + $1.00

$1.10 - $1.00 = 2 x Ball = $0.10

$0.10 / 2 = Ball = $ 0.05

Same goes for a combined total of $2.20.

 

[Blazin]

Or, a pick-up truck load.

Even a pile! :msp_wink:

 

[Fyrebug]

Dont know why you guys find this so difficult. It's quite simple really...

Let the cost of the ball = a
So the cost of the bat = a + 1
Total cost for both = a + (a + 1)
2a + 1 = 1.10
2a = 0.10
a = 0.05 (cost of ball)
a + 1 = 1.05(cost of bat)
Total = 1.05 + 0.05 = 1.10

Duh!

 

[Coldfront]

I get it now 5 cents. For a simple question that was quite tricky.

 

[MATTYB11]

Is the $1.10 price before or after my state adds 7% sales tax?

 

[Section VIII]

Still think it was a trick question. I originally thought that the answer was .10 without thinking more than 5 seconds. But then my confidence was lowered due to the fact that I answered too quickly. So...what exactly does the answer measure confidence-wise?

 

[TermiteBuffet]

I really need to know what kind of ball it is before i answer :msp_thumbsup:

 

[D&B Mack]

But in reality, the ball costs $ 1,429.72 after we pay the loan interest back to China. :hmm3grin2orange:

 

[pyankura]

My first post here but this one got me too....The answer is explained here better but this is a common question!

http://mitsloan.mit.edu/newsroom/newsbriefs-0605-frederick.phpa=ball


a+1=bat

total =1.10

a+a+1=1.10

Answer is .05

 

[Johny Utah]

By the way it was worded I have to say 10 cents. But if it meant they both separately cost $1.10 then the ball cost a $1.10

That's what got me is how do you know what cost what?