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Error on Friday's show

Posted: Sat Nov 13, 2010 2:45 am
by Bob78164
The transcript's not up yet so I'll put it in a spoiler box.
The error
The question asked: When gold reached $1,000 an ounce, if a 150 pound man were worth his weight in gold, how much would he have been worth?
A. $24,000 B. $240,000
C. $2.4 million D. $24 million

The intended answer was C. $2.4 million, calculated by multiplying $1000 by 150 pounds by 16 ounces per pound. But that's not right. Gold is priced per troy ounce, not avoirdupois ounce, and there are fewer than 15 troy ounces in an avoirdupois ounce (and exactly 12 troy ounces in a troy pound). So the correct answer to the question as asked is roughly $2.2 million.
For those who haven't yet seen the show or watched the transcript, you might be amused by where in the stack the question appeared. --Bob

Re: Error on Friday's show

Posted: Sat Nov 13, 2010 7:31 am
by MarleysGh0st
Spoiler
Yep, I noticed that right away. A dream question, to not only get it by doing math, but to be able to discuss how the question is wrong! :mrgreen:

http://en.wikipedia.org/wiki/Troy_ounce
The troy ounce is part of the troy weights system derived from the Roman monetary system. The Romans used bronze bars of varying weights as currency. An aes grave weighed equal to 1 pound. One twelfth of an aes grave was called an uncia, or in English an "ounce". Later standardization would change the ounce to 1/16 of a pound (the avoirdupois ounce), but the troy ounce, which is 1/12 of a troy pound (note that a troy pound is lighter than an avoirdupois pound), has been retained for the measure of precious metals. At 480 grains, the troy ounce is heavier than the avoirdupois ounce, which weighs 437.5 grains. A grain is 64.7989 milligrams (mg); hence one troy ounce is 31.1034768 grams (g) (exact by definition), about 10 percent more than the avoirdupois ounce, which is 28.349523125 g (exact).
All of which leads to an interesting pair of "trick" questions:

Which weighs more, an ounce of gold or an ounce of feathers? A (troy) ounce of gold.
Which weighs more, a pound of gold or a pound of feathers? An (avoirdupois ) pound of feathers.

Re: Error on Friday's show

Posted: Sat Nov 13, 2010 11:01 am
by Bob Juch
Bob78164 wrote:The transcript's not up yet so I'll put it in a spoiler box.
The error
The question asked: When gold reached $1,000 an ounce, if a 150 pound man were worth his weight in gold, how much would he have been worth?
A. $24,000 B. $240,000
C. $2.4 million D. $24 million

The intended answer was C. $2.4 million, calculated by multiplying $1000 by 150 pounds by 16 ounces per pound. But that's not right. Gold is priced per troy ounce, not avoirdupois ounce, and there are fewer than 15 troy ounces in an avoirdupois ounce (and exactly 12 troy ounces in a troy pound). So the correct answer to the question as asked is roughly $2.2 million.
For those who haven't yet seen the show or watched the transcript, you might be amused by where in the stack the question appeared. --Bob
Spoiler
That assumes that the 150 pounds are avoirdupois pounds, not troy ones. It it's 150 troy pounds the correct answer is $1.8 million.

Re: Error on Friday's show

Posted: Sat Nov 13, 2010 11:04 am
by Bob78164
Bob Juch wrote:
Bob78164 wrote:The transcript's not up yet so I'll put it in a spoiler box.
The error
The question asked: When gold reached $1,000 an ounce, if a 150 pound man were worth his weight in gold, how much would he have been worth?
A. $24,000 B. $240,000
C. $2.4 million D. $24 million

The intended answer was C. $2.4 million, calculated by multiplying $1000 by 150 pounds by 16 ounces per pound. But that's not right. Gold is priced per troy ounce, not avoirdupois ounce, and there are fewer than 15 troy ounces in an avoirdupois ounce (and exactly 12 troy ounces in a troy pound). So the correct answer to the question as asked is roughly $2.2 million.
For those who haven't yet seen the show or watched the transcript, you might be amused by where in the stack the question appeared. --Bob
Spoiler
That assumes that the 150 pounds are avoirdupois pounds, not troy ones. It it's 150 troy pounds the correct answer is $1.8 million.
Spoiler
When was the last time anyone used troy pounds to measure the weight of a man?
--Bob

Re: Error on Friday's show

Posted: Sat Nov 13, 2010 11:12 am
by Bob Juch
Bob78164 wrote:
Bob Juch wrote:
Bob78164 wrote:The transcript's not up yet so I'll put it in a spoiler box.
The error
The question asked: When gold reached $1,000 an ounce, if a 150 pound man were worth his weight in gold, how much would he have been worth?
A. $24,000 B. $240,000
C. $2.4 million D. $24 million

The intended answer was C. $2.4 million, calculated by multiplying $1000 by 150 pounds by 16 ounces per pound. But that's not right. Gold is priced per troy ounce, not avoirdupois ounce, and there are fewer than 15 troy ounces in an avoirdupois ounce (and exactly 12 troy ounces in a troy pound). So the correct answer to the question as asked is roughly $2.2 million.
For those who haven't yet seen the show or watched the transcript, you might be amused by where in the stack the question appeared. --Bob
Spoiler
That assumes that the 150 pounds are avoirdupois pounds, not troy ones. It it's 150 troy pounds the correct answer is $1.8 million.
Spoiler
When was the last time anyone used troy pounds to measure the weight of a man?
--Bob
Spoiler
When they put an man on one side of a scales and piled up the gold on the other.

Re: Error on Friday's show

Posted: Sat Nov 13, 2010 11:47 am
by BackInTex
"It's a trick question." says Mona Lisa Vito. "A man could never be worth his weight in gold. And even if he were, he'd weigh more than 150 pounds."