# 5th grade math question
**URL:** https://boards.straightdope.com/t/5th-grade-math-question/484056
**Category:** Factual Questions
**Created:** [February 2, 2009, 1:03am UTC](https://boards.straightdope.com/t/5th-grade-math-question/484056 "2009-02-02T01:03:14Z")
**Posts on this page:** 10
**Page:** 1
### Author:  [@tdn](https://boards.straightdope.com/u/tdn)
#### Post date: [February 2, 2009, 1:03am UTC](https://boards.straightdope.com/t/5th-grade-math-question/484056/1 "2009-02-02T01:03:14Z")
I was just watching the last bit of _Are You Smarter…_, and a guy decided to go for the million dollar question.
How many common factors do the numbers 24 and 32 have?
The contestant answered 2, which are 2 and 4. He lost the money.
I guessed 3. One of the students correctly answered 3, the factors being 1, 2, and 4. Had the contestant answered 3, he would have won.
Right?
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### Author:  [@mhendo](https://boards.straightdope.com/u/mhendo)
#### Post date: [February 2, 2009, 1:04am UTC](https://boards.straightdope.com/t/5th-grade-math-question/484056/2 "2009-02-02T01:04:54Z")
What about 8?
3x8=24
4x8=32
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### Author:  [@smiling\_bandit](https://boards.straightdope.com/u/smiling_bandit)
#### Post date: [February 2, 2009, 1:05am UTC](https://boards.straightdope.com/t/5th-grade-math-question/484056/3 "2009-02-02T01:05:37Z")
That is the “official” answer according to the show.
The problem is that there are different rules for factoring, and it was not clear which they were using. Many sources ignore “1”, because it always applies. Likewise, if they wanted to apply the 2 twice.
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### Author:  [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)
#### Post date: [February 2, 2009, 1:06am UTC](https://boards.straightdope.com/t/5th-grade-math-question/484056/4 "2009-02-02T01:06:00Z")
[This wasn’t a rerun, was it?](http://boards.straightdope.com/sdmb/showthread.php?t=486387)
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### Author:  [@N9IWP](https://boards.straightdope.com/u/N9IWP)
#### Post date: [February 2, 2009, 1:19am UTC](https://boards.straightdope.com/t/5th-grade-math-question/484056/5 "2009-02-02T01:19:26Z")
Yes, it was the rerun with “Hoot” Gibson.
Brian
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### Author:  [@Indistinguishable](https://boards.straightdope.com/u/Indistinguishable)
#### Post date: [February 2, 2009, 1:39am UTC](https://boards.straightdope.com/t/5th-grade-math-question/484056/6 "2009-02-02T01:39:41Z")
> [@mhendo](#):
>
> What about 8?
It looks like the actual numbers were 28 and 32, per **Thudlow Boink** ’s linked thread.
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### Author:  [@tdn](https://boards.straightdope.com/u/tdn)
#### Post date: [February 2, 2009, 1:39am UTC](https://boards.straightdope.com/t/5th-grade-math-question/484056/7 "2009-02-02T01:39:50Z")
> [@mhendo](#):
>
> What about 8?
>
> 3x8=24
> 4x8=32
That’s what’s at the heart of my question.
Why not 8?
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### Author:  [@eleanorigby](https://boards.straightdope.com/u/eleanorigby)
#### Post date: [February 2, 2009, 2:12am UTC](https://boards.straightdope.com/t/5th-grade-math-question/484056/8 "2009-02-02T02:12:48Z")
> [@tdn](#):
>
> That’s what’s at the heart of my question.
>
> Why not 8?
I am no math person, but I hazard to guess that it’s not 8 because 8 can be factored down into 4 and 2? I dunno. (and then 4 can be factored down to 2x2). The lowest common factor would be 2, right? (I don’t count 1). But to factor 24 and 32, it’s either 12 2s or 16 2s, OR some combo of 4 and 2.
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### Author:  [@Indistinguishable](https://boards.straightdope.com/u/Indistinguishable)
#### Post date: [February 2, 2009, 2:20am UTC](https://boards.straightdope.com/t/5th-grade-math-question/484056/9 "2009-02-02T02:20:16Z")
No, the reason 8 doesn’t count is because the number wasn’t actually 24; it was 28. The OP misremembered.
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### Author:  [@tdn](https://boards.straightdope.com/u/tdn)
#### Post date: [February 2, 2009, 2:03pm UTC](https://boards.straightdope.com/t/5th-grade-math-question/484056/10 "2009-02-02T14:03:52Z")
> [@Indistinguishable](#):
>
> No, the reason 8 doesn’t count is because the number wasn’t actually 24; it was 28. The OP misremembered.
That was the one **Thudlow** asked about. Yep, my bad.
Funnily enough, I rewound to make sure that the 2nd number was 32.