Core ConceptRead this first — the foundation of the topic
Box/Stack puzzles involve arranging items in a vertical stack or boxes on different floors. Items are placed one above the other based on given conditions. Think of it like stacking books or placing boxes in a tower.
Key RulesCore rules you must know cold
Only one item can occupy each position. Items are numbered from bottom to top or top to bottom. Conditions link items using words like 'above', 'below', 'immediately above', 'between', 'top', 'bottom'.
Key Properties: 'Immediately above' means direct contact with no gap. 'Above' means anywhere higher, with possible gaps. 'Between' means exactly one item separates two others. 'Second from top' means one item above it.
Exam PatternsWhat examiners ask — read before attempting PYQs
SSC asks 3-5 questions per puzzle. Common formats include 7-floor buildings, 8-box stacks, or 5-item arrangements. Questions test position identification, relative placement, and counting gaps between items.
ShortcutsUse these to save 30–60 seconds per question
Use the 'Fixed Point Method'. Find items with maximum constraints first. Items mentioned as 'top', 'bottom', or with multiple conditions become anchor points.
Build the arrangement around these fixed positions.
Worked ExampleSolve this step-by-step before moving on
1
Step 1
Fix definite positions. C is at position 7 (top). A is at position 6 (immediately below C). D is at position 1 (bottom).
2
Step 2
Analyze 'between' condition. B is between E and F means E-B-F or F-B-E arrangement.
3
Step 3
Use remaining condition. G is above E but below F. This gives us F-G-E sequence when read from top to bottom.
4
Step 4
Combine sequences. From F-G-E and E-B-F, we get F-G-E-B-F. But F cannot repeat, so we arrange as F-G-E-B with F above this group.
5
Step 5
Final arrangement from bottom to top: D(1), E(2), B(3), G(4), F(5), A(6), C(7).
Verification: C at top ✓, A immediately below C ✓, D at bottom ✓, B between E and F ✓, G above E but below F ✓.
Second Shortcut: Draw a rough vertical line and mark positions 1-7. Fill known positions first, then work with remaining conditions.
Exam TrapsCommon mistakes students make — avoid these
Students confuse 'above' with 'immediately above'. 'Above' allows gaps, 'immediately above' means direct contact. Also, misreading 'between' conditions leads to wrong sequences. Always verify final arrangement against all given conditions.
Key Points to Remember
Box puzzles arrange items vertically with one item per position
'Immediately above' means direct contact, 'above' allows gaps between items
'Between' means exactly one item separates two others in the stack
Use Fixed Point Method - identify items with maximum constraints first
Number positions from 1 (bottom) to n (top) or vice versa consistently
Draw vertical arrangements to visualize relationships clearly
Always verify final arrangement against every given condition
Common question types: position finding, gap counting, relative placement
Exam-Specific Tips
Box puzzles typically involve 5-8 items arranged vertically
SSC asks 3-5 questions per box arrangement puzzle
'Second from bottom' means position 2 when counting from bottom
'Third from top' means position 3 when counting from top
Maximum gap between two items in 7-box puzzle is 5 positions
Minimum items needed for 'between' relationship is 3 items
'Immediately below' means direct contact from lower position
Box puzzles appear in 80% of SSC CGL Tier-1 question papers
Practice MCQs
Box / Stack Puzzle — Practice Questions
4graded MCQs · easy to hard · full solution & trap analysis
Five boxes labeled A, B, C, D, and E are stacked vertically from bottom to top. The following conditions must be satisfied:
1. Box C is not at the bottom.
2. Box A is exactly 2 positions above Box B.
3. Box D is immediately above Box E.
4. Box C is above Box A.
Which box is at the top (5th position)?
Practice 2medium
Six books—Fiction (F), History (H), Mystery (M), Novel (N), Poetry (P), and Science (S)—are arranged on a shelf in positions 1 to 6 (left to right). The following conditions hold:
(i) Mystery is 3 positions to the right of History.
(ii) Poetry is immediately to the left of Science.
(iii) Novel is not in position 1.
(iv) Fiction is to the left of Mystery.
If History is in position 2, which book is in position 5?
Practice 3medium
Five boxes labeled A, B, C, D, and E are stacked vertically in positions 1 to 5 (1 = bottom, 5 = top). The following conditions apply:
(i) Box C is exactly 2 positions above Box A.
(ii) Box B is immediately above Box D.
(iii) Box E is not at the top.
(iv) Box A is not at the bottom.
Which box is at position 3?
Practice 4medium
Nine books are stacked in positions 1 to 9 (bottom to top). The books are labeled P, Q, R, S, T, U, V, W, X. The following conditions must be satisfied:
(i) Book R is exactly 4 positions above Book P.
(ii) Book S is immediately above Book T.
(iii) Book U is above Book W.
(iv) Book Q is not in position 1.
(v) Book V is in position 5.
If Book P is in position 2, which book is in position 6?
60-Second Revision — Box / Stack Puzzle
Remember: Fix definite positions (top/bottom/immediately) first
Formula: Total positions minus 1 equals maximum possible gaps
Trap: 'Above' and 'immediately above' have different meanings
Method: Use vertical line diagram for clear visualization
Check: Verify final answer against all given conditions
Shortcut: Items with most constraints become anchor points
Pattern: Between A and B means A-X-B or B-X-A arrangement