When two rules run at once in an abstract reasoning sequence

Worked solution

Correct answer: the first option

The principle

Two rules run at once: one dot is added at each step, and the dots occupy the corners of the square clockwise, starting from the top left.

Steps

1. Count the dots: 1, then 2, then 3. The fourth figure must therefore hold 4 dots.
2. Track their positions: top left; top left and top right; top left, top right and bottom right. Each new dot appears at the next corner, moving top left to top right to bottom right.
3. The next corner after bottom right in that rotation is bottom left, so the fourth figure has dots at all four corners with the new one at bottom left.
4. Only the correct figure shows four dots, one at each corner, and no dot anywhere else.

Heuristic to carry forward

When a sequence changes in more than one way, isolate each rule separately (count first, then position) and only then look for the option that satisfies every rule at once. An option that satisfies the count but breaks the position rule is the most common trap.

Why each other answer is wrong

the fourth option

Applies the count rule (4 dots) but places the new dot in the centre, breaking the corner-progression rule the first three figures establish.

the third option

Repeats the third figure unchanged, applying the position rule while forgetting that the count increases at every step.

the second option

Adds the fourth dot at the midpoint of the edge between bottom right and bottom left rather than at the bottom left corner, continuing the general direction but abandoning the corners the sequence has used throughout.