Non-Verbal Reasoning Odd One Out

The test shows you five figures. Four of them share a hidden rule. One breaks it, and that is your answer.

The question asks which figure is most unlike the other four. That sounds like a matter of opinion. It is not: there is always one thing that four of them do and the fifth does not.

So do not hunt the odd one. Hunt the four.

The method

Five beats: read five, find four, check the split, say the sentence, name the axis.

1. Read all five before you decide anything. The first figure you look at always has something unusual about it. That is not evidence.
2. Find what four of them share. Not what one of them lacks. Hunting the outsider means judging how strange things look. Hunting the group means counting, which you can prove.
3. Check the split. Every idea you have splits the five somehow. Only a four to one split can be the answer.
   • All five the same? Nothing. Cross it off out loud: "all five are black, so it is not the shade."
   • All five different? Nothing either. It was varied to catch your eye.
   • Three against two? Not the rule. Keep looking.
4. Say it the way the test says it. "All of them fold down the middle except this one, which does not." If you cannot finish that sentence, your rule is wrong.
5. Name the axis, not the figure. The answer is "the one that does not fold down the middle", not "the third one".

Count first. Sides, dots, parts, bends, corners. A count is fast and nobody can argue with it. About 20 to 25 seconds a question.

Rules to watch

Run the SHAPES+S scan across all five, asking the same thing each time: four to one?

• S — Shade. White, grey, hatched (thin diagonal lines) or black? The most common change of all. Shades swap, or one shape hands its shade to another. Judge a tone against the figure next to it, not from memory.
• H — How many. Count them. A shape can appear, vanish, split, double, or copy itself to each side.
• A — Angle. A quarter turn clockwise, a half turn, or reflected — flipped over like a mirror? Watch one corner. A turn walks it round the shape. A mirror jumps it straight across.
• P — Place. Moved, traded jobs, or gone inside? A small item becomes the big frame, the middle swaps with the corners, loose shapes tuck into containers, a whole ring shifts one place clockwise.
• E — Edges. A different shape? More sides? A solid line gone dashed?
• S — Size. Bigger or smaller?
• +S — Symmetry. Does the figure fold onto itself? Down the middle, across the middle, or the same upside-down. Fold the whole figure, not just its outline. A favourite here — it is one of the most common odd-one-out rules there is, so never leave it out.

If none of those splits four to one, the rule is about how two parts go together. That is the hard end of this type, where most exam-level questions live.

• Touching, crossing or inside? Do two shapes share a slice, meet at one point, or sit one within the other?
• Which one is in front? At the crossing, one outline is broken. That one is behind.
• Where is it, in its own figure? Next to the shortest side. One step clockwise from a gap. Never "top left of the box".
• How big is it, next to its own outline? A small core, or nearly filling it.
• Does one part match another? Two copies that should agree, and in one figure they do not.

Watch for these traps

• A difference on an axis where everything differs. Much the most common, planted on purpose. All five shapes are different kinds, or sizes, or directions, and one is bound to catch your eye. But if all five differ, no figure is odd there.
• A part that means nothing at all. A dot or an extra edge, put there to be looked at. Every other question type taught you a difference is a clue. Here, some are furniture. Test it: four to one?
• A mirror mistaken for a turn. The hardest fair trap there is. Four figures are one design turned round, the fifth is flipped. Follow a mark off to the side clockwise round each figure: turning keeps the order, a mirror puts it back to front.
• Touching read as overlapping. At small size a shallow overlap and a touching point look almost the same. Look for one outline passing through another. If no line crosses, they only touch.
• Symmetry taken from the outline. The outline folds in half, so the figure feels symmetrical. Fold the whole figure.
• Size judged against the row. The biggest figure stands out, but the outlines are all different sizes on purpose. Compare each inner shape with its own outline.

Try these yourself

Now have a go yourself — tap the figure that is the odd one out.

Related

• The complete 11+ question-type guide
• NVR: Similarities — the same game the other way round
• NVR: Series — find the rule across a row of shapes

All example questions come from the Brainblox question bank — practise this question type inside 15 arcade games, timed mock exams and focused practice. Brainblox is an independent app: not affiliated with, endorsed by or licensed by any exam board, school or assessment publisher, and it contains no past papers.