Start here — one guess
Look at this for 20 seconds. The third cell in each row comes from combining the first two. What goes in the empty cell?
If you're not sure how the cells combine yet, good — that's the whole chapter. The one thing to notice: the third cell isn't a copy of either input. It's built from both.
Sit with it for twenty seconds. The answer to this one lives in the chapter drill rather than on the page.
The family in one sentence
Combining: the third cell is the first two cells combined by a set rule — kept, shared, or cancelled.
The cells are made of marks (dots, lines, small shapes). The third cell holds some of the marks from the first two, chosen by one rule. Your whole job is to name the rule.
The four set rules: keep everything (union), keep only the shared marks (intersection), keep the unshared marks (XOR), or remove the second from the first (difference).
What Combining looks like
- The first two cells in a row (or column) are the inputs. The third is the result.
- The result uses the same kind of marks as the inputs — it just keeps a different selection of them.
- Nothing rotates, grows, or moves. The only question is which marks survive.
There are four rules in this family, and they differ only in which marks the result keeps:
- Union (OR) — keep every mark that's in either input.
- Intersection (AND) — keep only marks that are in both.
- XOR — keep marks that are in exactly one input (drop the shared ones).
- Difference — keep the first cell's marks that are not in the second.
Full access
Combining and overlap: the rest of this chapter is part of full access
You have read the lead-in. The tactics, the worked questions, the discrimination quiz, the cheat sheet and the reference card sit behind one payment, together with all eight chapters, their drills and mastery checks, a second form of every practice test, and the review queue.
$29 once · 12 months · 30-day refund
The course
This chapter is a lesson in the Matrigma Prep Course
The course carries the same eight chapters as ten pattern lessons, each with a guided think-through, a drill of unseen questions and a quiz, plus the full practice tests and your readiness report. Enrolling is free; full access opens the paid lessons.
Where to practise
The drill serves ten combining and overlap questions you have not seen, easiest first, with the explanation after every answer. The mastery check is six questions — two easy, two medium, two hard — at sixty seconds each, with no tactic on screen and no explanations until the end.