Math test.

[fantome profane]

9 = 90
8 = 72
7 = 56
6 = 42
3 = ?

 

[Stevicus]

3=3

 

[We Never Know]

9 = 90
8 = 72
7 = 56
6 = 42
3 = ?

12?(if including 4 and 5)

Or 30?(if not including 4 and 5

 

[Left Coast]

9 = 90
8 = 72
7 = 56
6 = 42
3 = ?

X=12

I didn't look at any other answers I swear!

 

[Subduction Zone]

12

 

[fantome profane]

@Stevicus

Spoiler

I like your answer. It is like that old riddle, how many legs does a dog have if we say the tail is another leg?

But, although I like your answer, I ask, is there any other possible answer you could think of?

@We Never Know

Spoiler

Interesting. I am not saying you are wrong, I am not saying you are right. But how did you come up with "30"?

@Left Coast and @Subduction Zone

Spoiler

Are you sure?

I am going to bed now. Goodnight.

 

[Subduction Zone]

@Stevicus

Spoiler

I like your answer. It is like that old riddle, how many legs does a dog have if we say the tail is another leg?

But, although I like your answer, I ask, is there any other possible answer you could think of?

@We Never Know

Spoiler

Interesting. I am not saying you are wrong, I am not saying you are right. But how did you come up with "30"?

@Left Coast and @Subduction Zone

Spoiler

Are you sure?

I am going to bed now. Goodnight.

There is often more than one answer to these sorts of questions. So you may be using a different algorithm. This is the result of the first one that came to my mind. I will put the equation into a spoiler:

Spoiler

y = x*(x+1)

I am not going to declare any other answer wrong.

 

[icehorse]

9 = 90
8 = 72
7 = 56
6 = 42
3 = ?

12?

 

[We Never Know]

@Stevicus

Spoiler

I like your answer. It is like that old riddle, how many legs does a dog have if we say the tail is another leg?

But, although I like your answer, I ask, is there any other possible answer you could think of?

@We Never Know

Spoiler

Interesting. I am not saying you are wrong, I am not saying you are right. But how did you come up with "30"?

@Left Coast and @Subduction Zone

Spoiler

Are you sure?

I am going to bed now. Goodnight.

To answer your question
5=30
4=20
3=12

But if you leave out 4 and 5
6=42
-12
3=30

 

[Stevicus]

@Stevicus

Spoiler

I like your answer. It is like that old riddle, how many legs does a dog have if we say the tail is another leg?

But, although I like your answer, I ask, is there any other possible answer you could think of?

@We Never Know

Spoiler

Interesting. I am not saying you are wrong, I am not saying you are right. But how did you come up with "30"?

@Left Coast and @Subduction Zone

Spoiler

Are you sure?

I am going to bed now. Goodnight.

18?

 

[Altfish]

9 = 90
8 = 72
7 = 56
6 = 42
3 = ?

From the small sample provided the formula seems to be n=n(n+1)
So, the answer is 12

 

[RestlessSoul]

18?

^^ This (3x6)

Or, if there are two lines missing, 12 (4x3)

 

[Curious George]

9 = 90
8 = 72
7 = 56
6 = 42
3 = ?

18 if we take the left side and multiply by the number above to get the number on the right side of the = sign.

alternatively 12 if they are stand alone. (3+2+1)*2=12 or 3*(3+1)=12

 

[exchemist]

12?(if including 4 and 5)

Or 30?(if not including 4 and 5

n(n+1)? If so 12.

 

[lewisnotmiller]

N = n squared + n.

12

 

[Aštra’el]

12

Spoiler

Also 18.

 

[ChristineM]

Obviously 3 = "?" It says so right there in the OP

 

[Mock Turtle]

Multiply left by two, subtract from right, decrement left, place result of subtraction, continue ... hence 12

 

[Jayhawker Soule]

y = x * (x + 1)

 

[fantome profane]

@Stevicus @We Never Know @Left Coast @Subduction Zone @icehorse @Altfish @RestlessSoul @Curious George @exchemist @lewisnotmiller @Aštra’el @ChristineM @Mock Turtle @Jayhawker Soule


Thanks to all who replied. You have all been participating (against your will of course) in a psychological experiment disguised as a math question. And I am happy to say you all passed (whatever that means).

The correct answer is

Spoiler

The answer is "12 or 18". The correct answer is not 12. And the correct answer is not 18. The correct answer must be "12 or 18".

Or the other correct response is simply to say that the question is flawed and cannot be answered.

But I am glad to see that no one fought over the answer. No one went to war over this. So congratulations to all.