casework-by-position-type
Positions in a configuration (squares on a grid, vertices of a polyhedron) split naturally into a small number of symmetry classes (corner / edge / center; edge-neighbor / face-diagonal / space-diagonal). Counting attacks each class separately and sums via the multiplication principle.
풀이 전략
- Move from 3x3 chess grid to 4x4 — corner/edge/middle counts shift but the casework strategy is identical
- Replace kings with knights (different attack pattern) so the per-class counts change
- On the cube, ask for equilateral triangles NOT containing P, or right triangles containing P
세부 유형 분포 (5)
한 줄을 클릭하면 그 안의 문제를 볼 수 있어요.
- grid-cell-position 36% (13)
A 2D grid or 3D solid is divided into cells (or cubes) that fall into structurally distinct classes based on how many boundary faces they touch (corner, edge, face-center, interior). Casework runs over these position classes and sums the count for each.
- digit-place-position 14% (5)
A multi-digit number is analyzed by splitting cases on which digit position (units, tens, hundreds, or a rank like median/maximum) holds the constrained value. Each possible slot is one structural case.
- vertex-or-element-role 22% (8)
A small fixed set of elements (vertices of a shape, people in a group, points in a figure) is divided by which one plays a constrained structural role (right-angle vertex, driver, symmetric anchor). Casework exhausts the possible role-holders.
- count-of-type 14% (5)
A configuration is split into cases by how many elements of a given kind appear (0, 1, 2, … up to a maximum). Each possible count defines one structurally distinct case, and the totals are summed.
- arrangement-block-type 14% (5)
Objects of two (or more) types are arranged in a line, circle, or grid, and the arrangement is classified by the pattern of consecutive same-type blocks (LLLRRR vs LRRRLL vs LRRLLR, etc.). Casework runs over the distinct block-sequence shapes.
더 보기 (연도 추세, 도구 fingerprint, 학년 분포, 전체 문제)
도구 fingerprint (1–17)
학년 분포
- Gr 3 3
- Gr 4 9
- Gr 5 3
- Gr 6 4
- Gr 7 11
- Gr 8 5