Brain Training "Just Numbers"

[Optic101]

Weekend Exercise.

[PapaDisco]

6

[dangolf18]

That 20 should be a 15 and it's impossible to know what the ? number is.

[HarveyBoulevard]

6

[Jeremy Festa]

9

Sent from my iPhone

[Erm310mce]

9

[backslide]

15

Sent from my Nexus 5

[PigFish]

6

[Jeremy Festa]

That 20 should be a 15 and it's impossible to know what the ? number is.

Nothing is impossible

Sent from my iPhone

[MC4]

6

[westg]

8

[Alien13]

That 20 should be a 15 and it's impossible to know what the ? number is.

*SPOILER*

The 5 = 20 is correct.

It's simply x = x * x - x

5 = 5 * 5 - 5

5 = 25 - 5

5 = 20

So with that in mind.

3 = 6

[shlomo]

Edit. Just 6.

[dangolf18]

*SPOILER*

The 5 = 20 is correct.

It's simply x = x * x - x

5 = 5 * 5 - 5

5 = 25 - 5

5 = 20

So with that in mind.

3 = 6

Oh duh I see it now. I saw the pattern but was wondering why the 4 wasn't there. Definitely 6.

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[garbandz]

"That 20 should be a 15 and it's impossible to know what the ? number is."

or this if you missed the pattern completely..............

[Phillys]

6

[Dozerhead]

6

[Optic101]

Well done guys.

X * (X-1)

? = 6

Or the "manual" way

8 = 56 > 7

7 = 42 > 6

6 = 30 > 5

5 = 20 > 4

3 = > 2

3 x 2 = 6

[Perla]

12

[Jeremy Festa]

****! Trick question! Solved it as if it was 4!

Sent from my iPhone

[alpyigit]

6

[Perla]

Well done guys.

X * (X-1)

? = 6

Or the "manual" way

8 = 56 > 7

7 = 42 > 6

6 = 30 > 5

5 = 20 > 4

3 = > 2

3 x 2 = 6

Are you sure?

It also could be:

8= 56 -14

7= 42 -12

6= 30 -10

5= 20 -8

3= 12

[shlomo]

Are you sure?

It also could be:

8= 56 -14

7= 42 -12

6= 30 -10

5= 20 -8

3= 12

Great!

[ayepatz]

Yes. I understand none of this. I shall have a cigar instead.

[Optic101]

Are you sure?

It also could be:

8= 56 -14

7= 42 -12

6= 30 -10

5= 20 -8

3= 12

Very good point.

8= 56

14

7= 42

12

6= 30

10

5= 20

8

3= 12

What does not work with this approach is that there is an asynchrony step on the left side (5 to 3) while the right side is fully synchron.

IMHO