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## Help with teaser

AuthorMessage
21kaldridge21

Posts: 231

 Posted: 01:28PM Apr 24, 2013

I found this on Facebook and really want to know the answer.

It said 98% will fail

2 = 6
3 = 12
4 = 20
5 = 30
6 = 42
9 = ??

I'm back
jaycr

Posts: 2233

 Posted: 04:47PM Apr 24, 2013

I believe 9 = 90
Look for a pattern.

It's not what you know, it's what people think you know.
Innovative

Posts: 76

 Posted: 06:51PM Apr 24, 2013

Solved it too.

Here's a hint: (Very small)

result / initial number

---This message was edited on 06:51PM Apr 24, 2013---

"This thaw took a while to thaw, it's going to take a while to unthaw." -George W. Bush, on liquidity in the markets.
RGW4

Posts: 1241

 Posted: 08:05PM Apr 24, 2013

72

A person who never made a mistake never tried anything new. -Albert Einstein-
jaycr

Posts: 2233

 Posted: 08:31PM Apr 24, 2013

RGW, I guess that would work too. There could be two answers. Agreed?

It's not what you know, it's what people think you know.
RGW4

Posts: 1241

 Posted: 10:22PM Apr 24, 2013

Jay, I am sure there could be, how did you come up with 90?

In fact, I was actually trying to figure how you came up with 90 when I saw a pattern.

What appeared to be missing was what made 2 = 6... a missing 3 times 2 = 6
The next missing number is 4 times, then 5 times... down to the last number where 8 times 9 = ?? or 72.

Edit because I had my numbers backwards, no incorrectly stated

---This message was edited on 05:33PM Apr 26, 2013---

A person who never made a mistake never tried anything new. -Albert Einstein-
jaycr

Posts: 2233

 Posted: 05:51AM Apr 25, 2013

7 and 8 are missing but I kept them in the pattern for my answer. Does that make sense?

It's not what you know, it's what people think you know.
21kaldridge21

Posts: 231

 Posted: 12:04PM Apr 25, 2013

I got 90 for my answer too.

Here is how I did it
2 x 3 = 6
3 x 4 = 12
4 x 5 = 20
5 x 6 = 30
6 x 7 = 42
7 x 8 = 56
8 x 9 = 72
9 x 10 = 90

My mom also tried to figure it out and got 90 a different way.

Here is my mom did it
12 - 6 = 6
20 - 12 = 8
30 - 20 = 10
42 - 30 = 12
42 + 14 = 56
56 + 16 = 72
72 + 18 = 90

But I don't think this is right since it said 98% of people will get this wrong so if so many people are getting 90 as the answer then that can't be right.

I'm back
RGW4

Posts: 1241

 Posted: 05:52PM Apr 25, 2013

Interesting way of solving the puzzle... I didn't add in two extra numbers because frankly, the way the question was put it wasn't looking for an endless sequence.

I think it's safe to say one of our answers is the "correct" one and one is wrong. Now how did the majority vote?

A person who never made a mistake never tried anything new. -Albert Einstein-
celtichero

Posts: 791

 Posted: 08:34PM Apr 25, 2013

I also got 90. Still don't quite get the 72 answer.

Also, kal, I think you were lied to on the Internet.

I'm just an ordinary average guy with nothing to lose.
JQPublic

Posts: 1832

 Posted: 08:51AM Apr 26, 2013

I think Randy misread the teaser since it said 2 = 6 and not 3 = 6. Since they said 98% will fail, I think we can safely assume it isn't 90, either.

There's probably a trick in the equal sign. Has anyone heard of this one:

1 = 1
2 = 4
3 = 9
4 = ?

We're assuming it's a sequence when, presented in such a manner, it may not be. What we've been doing so far is assuming f(2) = 6, and looking for f(x). What we should actually do is to think out of the box, IMO ...

---This message was edited on 08:56AM Apr 26, 2013---

'An idea, like a ghost, must be spoken to a little before it will explain itself.' - Charles Dickens
21kaldridge21

Posts: 231

 Posted: 09:09AM Apr 26, 2013

celtichero wrote:
I also got 90. Still don't quite get the 72 answer.

Also, kal, I think you were lied to on the Internet.

I think they get the 72 like this:
2 x 3 = 6
3 x 4 = 12
4 x 5 = 20
5 x 6 = 30
6 x 7 = 42
7 x 8 = 56
9 x 8 = 72

But if you look at the pattern you would know that is wrong.

---This message was edited on 09:12AM Apr 26, 2013---

I'm back
SliceOPi

Posts: 273

 Posted: 01:28AM Jun 26, 2013

98% will fail because they will continue to be wrong while the remaining 2% will realize that there is no correct answer and stop trying.

The life of man, solitary, poor, nasty, brutish, and short.
Steve1973

Posts: 822

 Posted: 02:21PM Jun 30, 2013

21kaldridge21 wrote:
I found this on Facebook and really want to know the answer.

It said 98% will fail

2 = 6
3 = 12
4 = 20
5 = 30
6 = 42
9 = ??

2 = 6. START
3 = previous number (6) + 1 + UP_ONE_ON_LEFT(2) + CURRENT_LEFT (3) = 12
4 = 12 + 1 + 3 + 4 = 20
5 = 20 + 1 + 4 + 5 = 30
6 = 30 + 1 + 5 + 6 = 42
9 = 42 + 1 + 6 + 9 = 58

OR
2 = 6 START
3 = PREVIOUS NUMBER (6) + 2 * CURRENT NUMBER(6) = 12
4 = 12 + 8 = 20
5 = 20 + 10 = 30
6 = 30 + 12 = 40
9 = 40 + 18 = 58

Who says we need to continue the pattern for 7 and 8? That's not the question.... 98% get it wrong, because 58 is the answer.

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Steve1973

Posts: 822

 Posted: 03:08PM Jun 30, 2013

OR

2 = 6 START
3 = CURRENT NUMBER ^ 2 (9) + PREVIOUS NUMBER ON LEFT (2) + 1. = 12
4 = 16 + 3 + 1 = 20
5 = 25 + 4 + 1 = 30
6 = 36 + 5 + 1 = 42
9 = 81 + 6 + 1 = 88

Math is all about sequence manipulation of numbers. I'd say 90, 58, 88, and several more numbers could fit this pattern. Since 98% of people are supposed to get this wrong, I'd say 90 is the incorrect answer since its the obvious one. (F(n) = n ^ 2 + n)

What the correct answer is then? I guess that depends on if you're creative enough to find a working pattern that isn't in the 98%.

Like to chat? Share links? Don't want to be told, it's a No-No to do so? Then come join us in THE REAL GENERAL DISCUSSION talkbox -- where you can post with only the lightest of moderation.
MDCTeasers

Posts: 1884

 Posted: 12:02AM Apr 8, 2014

I came up with 90.

1 = 4
2 = 6
3 = 12
4 = 20
5 = 30
6 = 42
7 = 56
8 = 72
9 = 90

I added 1, 7, and 8. But: here's how it makes sense. IGNORE THE FIRST NUMBERS. And... add 2 to 4. What is the sum? 6. Keep adding 2 to the number you added before. So...

4+2=6
6+6=12
12+8=20
8+2=10*
10+20=30
10+2=12*
30+12=42
12+2=14*
42+14=56
14+2=16*
56+16=72
16+2=18*
72+18=90

Now look at the bold numbers and... surprise!!! They match the answers! So that's MY method... but probably I'm one of the 98% wrong. Or maybe they meant 98% are right? Anyway, please everyone share their methods and answers (which most will probably be 90)!

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