Keyholes (officially Apertures) is the first PAT subtest. Each question shows a solid object and five openings, and you pick the one opening the object could pass straight through.
PAT Grind has 1,200 keyholes questions at three difficulty levels. Each one is checked by an independent solver and comes with a step-by-step explanation.
How the questions work
- You may turn the object any way you like before it enters the opening, including entering from a side you can't see.
- Once it starts through, it can't twist or turn, and it must pass all the way through.
- The correct opening is the exact outline of the object seen along one of its principal directions. Object and openings are drawn to the same scale.
- Hidden parts of the object hold no surprises: features you can see run straight through, and symmetric indentations are symmetric on the hidden side.
Strategy
- Before looking at the options, picture the three outlines: from the top, from the front and from the side. The answer is one of them, possibly rotated or flipped over.
- Count the steps, notches and slanted edges along each side of an opening, then compare against your outlines. A single extra notch rules an option out.
- Check proportions. A wrong opening is often the right shape stretched or squashed by one unit.
- Eliminate quickly: if an opening has a feature the object can't produce from any direction, cross it off and move on.
Common traps
- A notch shifted to the wrong position along an edge.
- A slanted edge drawn as a square step, or a step drawn as a slant.
- An outline that is almost right but slightly too small, so the object can't fit.