# Which number replaces the question mark in <16, 2, 11, 6, 9, 4, 14, ?>

I came across a puzzle (posed by my friends) that looked like this:

Which Number Replaces the Question Mark?

     6
11 | 9
\|/
2 -- ⬤ -- 4
/|\
16 | 14
?

• A. 1
• B. 2
• C. 3
• D. 5

Does anyone see any pattern here?

I would guess that the question mark should be:

$$1$$

The pattern I see:

The picture is a tilted square, standing on one of its corners.
Along each edge of the square, the sum of the three numbers is $$19$$.
$$2+11+6=19$$, and $$6+9+4=19$$, and $$4+14+?=19$$, and $$?+16+2=19$$

• Yup. Actually the puzzle is very nice example how visuals can be used as red-herrings in this type of things. It is so hard to ignore the lines... Feb 8, 2015 at 17:21
• @BmyGuest And that exactly what, in my opinion, makes this a bad puzzle.
– xnor
Feb 10, 2015 at 0:06
• You are great, Gamow. The line leading to center is blinding me .... Feb 18, 2015 at 0:59

I'd say:

1

Reasoning:

the difference between the opposing pairs are rising primes. 2-4 (2) 11-14 (3) 1-6 (5) 16-9 (7)

• if I am not wrong - in this way two possible answers are option A and C Feb 9, 2015 at 12:32
• He said rising, 3 is not rising. Feb 9, 2015 at 14:01

Diffenrence in right left top and bottom is two (9,11 and 14,16), and left right 2,4. Vertical it's five, so I guess, as mentioned above, it's one (1,6).

2

Looking at opposites and ignoring the sign, starting at the '2' and rotating clockwise

2 - 4 = 2

11 - 14 = 3

6 - ? = should be 4 therefore the number required is 2

9 - 16 = 5

I know this is not the answer being looked for, but another pattern :)

• How much is 9 - 16 again? Feb 9, 2015 at 13:59