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IQ Question 1

xtreme2k

Diamond Member
Jun 3, 2000
3,078
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0
There are 5 bags of gold coins, each bag as a large amount of gold coins in them. 1 bag of gold coins are fake. A REAL gold coin weights 100grams, fake gold coin weights 99grams.

Using an ACCURATE scale (note: not a balance), how would you determine which bags are real, and which bag is fake, by taking only 1 reading from that accurate scale? remember you can only take 1 reading.


 

Napalm381

Platinum Member
Oct 10, 1999
2,724
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Take one coin from the first bag, two from the second, etc, and place them on the scale. The number of grams that the scale is off from the expected value will correspond to the bag, i.e. if the scale is low by 4 grams, the fourth bag is the fake one.
 

fragarific

Golden Member
Sep 29, 2000
1,355
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I second that.

I would have said, put 4 bags on the scale. If your lucky enough to get the amount you should if they were all gold. The non-weighed one is fake.

 

Demon-Xanth

Lifer
Feb 15, 2000
20,551
2
81
Number the bags 1-5
put one coin from bag one
two from bag two
three from bag thre
four from bag four
five from bag five
1499 grams means bag 1 is fake
1498 grams means bag 2 is fake
1497 grams means bag 3 is fake
1496 grams means bag 4 is fake
1495 grams means bag 5 is fake
 

Napalm381

Platinum Member
Oct 10, 1999
2,724
0
0
You want a tricky question?

1. Develop a Grand Unified Theory of physics. Cite appropriate references. You have one hour. No calculators allowed. ;)
 

qacwac

Senior member
Oct 12, 2000
408
0
0
I didn't get it but I didn't spend to much time on it.
I didn't get the goat and car thing either until somebody explained.

conclusion: School is making me dumber.
 

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