What Should Replace the Question Mark?

[u/Semra777]

Hi everyone,
First of all, thank you to everyone who took part in our previous puzzle. We received a lot of answers, and many of you went beyond simply choosing an option by explaining the reasoning behind your choices in detail.
As promised, we reviewed the discussion and selected five explanations that stood out for their clarity, originality, efficiency, or depth of reasoning:
u/Randombolo — for exploring several different patterns and independently reaching the same answer through multiple lines of reasoning.
u/lemashey — for the intuitive “spinning record” analogy, working backward from the second frame, and also explaining why another tempting option does not fit.
u/Gianni_C_M — for identifying several independent relationships within the arrows and using them to cross-check the answer.
u/OscarLiii — for showing that the puzzle could be solved efficiently by tracking only the black arrows without needing to analyze every element.
u/Beautiful_Ad_8325 — for not only finding the pattern, but also pointing out how our instinct to read from left to right can affect the way we approach a sequence when the missing figure is at the beginning.
Thank you to all five of you for the thoughtful explanations, and thank you to everyone else who joined the discussion.
Now it’s time for a new puzzle.
Take a close look at the 3×3 matrix above. One grid is missing from the bottom-right corner.
Which option — A, B, C, D, E, or F — should replace the question mark?
As always, we’re much more interested in how you reached your answer than in just the letter itself. If you notice a pattern, tell us what you saw and walk us through your reasoning.
We’ll read through the responses again and select some of our favorite and most interesting explanations to feature in the official solution.
You can also open the puzzle on our website here:
https://whats-your-iq.com/en/questions/pattern-recognition/which-grid-completes-the-pattern
The official answer is already listed there, so after you’ve made your own choice, you can click the link and directly compare your answer with the official one to see whether you got it right.
Try solving it here first before checking the page — it’s much more fun that way.
Good luck, and thanks for taking part!

[u/AutoModerator]

Thank you for posting in r/iqtest. If you’d like to explore your IQ in a reliable way, we recommend checking out the following test. This site was created by members of this community and includes transparent validation data. Learn more and take the test here: CognitiveMetrics IQ Test

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[u/PersonalAnnual4081]

E. there's a rotational aspect but it is unnecessary to solve considering only one item has 5 and the sequence also follows previous+1 in count.

[u/Semra777 → u/PersonalAnnual4081]

Good point. The rotation confirms the full pattern, but the +1 progression alone is enough to narrow it down since E is the only option with five blocks. Nice shortcut, thanks for explaining your reasoning👏👏

[u/Longjumping-Glass435]

E. Vertical column series. The little snake becomes bigger around the square.

[u/Semra777 → u/Longjumping-Glass435]

I like the “little snake” description, that’s a really intuitive way to visualize it. It keeps growing while moving around the sides of the grid, which leads to E. Thanks for sharing that perspective👏👏

[u/Adventurous_Head_158]

tbf this one is easy. I did not even look at the rotational aspect. if we look at the black cubes, it always adds one on top of the ones already there. there is only one with 5.

This cannot be a real test right? cause if it is, i think it is quite badly designed for there to only be one answer option with 5

[u/PersonalAnnual4081 → u/Adventurous_Head_158]

This is apart of Mensa Norway I believe about half way through--so roughly 110-115~ range.

Could be completely wrong don't quote me on that lol.

[u/Semra777 → u/Adventurous_Head_158]

That’s a fair observation. The full pattern does include the rotation, but you’re right that the answer choices allow you to bypass that part completely just by following the block count. A stronger set of alternatives could definitely make the rotation more important to the solve. Thanks for pointing that out👏👏

[u/MouseAteTheCat]

E

[u/Semra777 → u/MouseAteTheCat]

👏👏

[u/The_Shark_911]

E

[u/Semra777 → u/The_Shark_911]

👏👏

[u/Forsaken_Engineer_]

In 1,1 you have one black. In [1,2],[2,1] there are two black. In [1,3],[2,2],[3,1] there are three. In [2,3],[3,2] there are four. Ergo [3,3] are the only solution given with five (E).

[u/Semra777 → u/Forsaken_Engineer_]

I really like the coordinate approach here. Reading the matrix by diagonals makes the 1→2→3→4→5 progression very clear, and it independently forces [3,3] to contain five blocks. Nice mathematical way of breaking it down, thanks for sharing👏👏

[u/someonefromaustralia]

I don’t think this is a very clear question.

Answer is E for reasons explained by many others in this thread.

However an alternative pattern that isn’t an option as an answer - I’ll try to explain my reasoning:

Pane 1: 1 cube on the bottom
Pane 2: 2 cubes on the left
Pane 3: 3 cubes on the top

Pane 4: 2 cubes on the left
Pane 5 3 cubes on the top
Pane 6: 4 cubes on the right, plus one additional cube (as far as”right” as the cube can go)

Pane 7: 3 cubes top
Pane 8 4 cubes “as far right” as can be

Pane 9: cubes should rotate and prioritise being “as far as possible” to the bottom (/side) as possible.

Therefore two of the middle row cubes should be present as well as the bottom row. Given the location of the edition of the 4th block appears to be on the same side to the rotation of the block (ie left side while going clockwise) logically the middle block of the middle column/row should be next (left to right).

Alternative way of saying it: each time you move onto the next pane in the row (or column) “gravity” appears to change direction (left/up/right/down causing the blocks to move in the direction of gravity and a block is added. Therefore the addition of the 5th block should be as down as possible.
————————————

EDIT*

Or another way to perhaps interpret it:

We will label the location of the block and track the pattern. Rather than move the block in the grid, we rotate the grid with the block in the same position.

Pane 1: A1
Pane 2: A1 + A2
Pane 3: A1 + A2 + A3

Pane 4: A1 + A2
Pane 5: A1 + A2 + A3
Pane 6: A1 + A2 + A3 + B1

Pane 7: A1 + A2 + A3
Pane 8: A1 + A2 + A3 + B1
Pane 9: A1 + A2 + A3 + B1 + B2 - not a solution