Antigravity Agent
f8b21af4be
10_Wiki/Topics 대규모 정리: - 오류 캡처/미완성 stub 문서 227개 제거 - 교차폴더 중복 43클러스터 병합 (63파일 → redirect) - 링크명 정규화: 깨진 링크 수정·redirect 직결·개념 매핑 ~2,400건 - 카테고리 MOC 6개 신규 생성 - Graph 섹션 미해결 related-keyword 링크 10,058건 제거 Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
156 lines
5.7 KiB
Markdown
156 lines
5.7 KiB
Markdown
---
|
||
id: wiki-2026-0508-problem-solving-test-pst
|
||
title: Problem Solving Test (PST)
|
||
category: 10_Wiki/Topics
|
||
status: verified
|
||
canonical_id: self
|
||
aliases: [PST, McKinsey PST, Consulting Problem Solving Test]
|
||
duplicate_of: none
|
||
source_trust_level: A
|
||
confidence_score: 0.85
|
||
verification_status: applied
|
||
tags: [consulting, mckinsey, structured-thinking, mece, problem-solving]
|
||
raw_sources: []
|
||
last_reinforced: 2026-05-10
|
||
github_commit: pending
|
||
tech_stack:
|
||
language: N/A
|
||
framework: MECE / Hypothesis Tree / Issue Tree
|
||
---
|
||
|
||
# Problem Solving Test (PST)
|
||
|
||
## 매 한 줄
|
||
> **"매 McKinsey legacy paper test — 26 case-style multiple-choice questions in 60 minutes — replaced by Solve / Imbellus game in 2018-2019, but the underlying skills (structured thinking, MECE, hypothesis-tree, data interp) 매 still core to consulting interviews"**. The test is gone; the discipline 매 not.
|
||
|
||
## 매 핵심
|
||
|
||
### 매 history
|
||
- **1990s-2017**: McKinsey PST = pen-and-paper screening before 1st round interview.
|
||
- **2018-2019**: replaced by **Solve** (formerly Imbellus) — game-based assessment (ecosystem balancing, plant defense).
|
||
- **2026**: Solve still in use; many regions also use video-interview AI screening; some clones (BCG Online Case, Bain SOVA, Deloitte Pymetrics).
|
||
- The PST format 매 still copied by other firms / business schools.
|
||
|
||
### 매 question types (PST format)
|
||
1. **Word problems**: "Client X has revenue $Y, costs $Z..."
|
||
2. **Data interpretation**: read chart/table → infer.
|
||
3. **Logic / reading**: assumption identification, what-if.
|
||
4. **Math**: %, ratios, breakeven, growth rates.
|
||
|
||
### 매 core consulting frameworks (the actual skill)
|
||
- **MECE**: Mutually Exclusive, Collectively Exhaustive — no overlap, no gap.
|
||
- **Issue tree**: hierarchical decomposition of the problem.
|
||
- **Hypothesis tree**: tree where each node is a falsifiable hypothesis.
|
||
- **80/20 / Pareto**: focus on biggest drivers first.
|
||
- **Profit tree**: Profit = (P - VC) * Q - FC; decompose each.
|
||
- **Market sizing**: top-down (population × penetration × ARPU) vs bottom-up.
|
||
|
||
### 매 modern Solve game
|
||
- 6 mini-games: ecosystem, redrock study, plant defense, etc.
|
||
- Measures: critical thinking, decision making, situational awareness, learning agility.
|
||
- AI-graded; ~70 min total.
|
||
|
||
## 💻 패턴
|
||
|
||
### MECE issue tree (text representation)
|
||
```
|
||
Problem: "Why is profit declining?"
|
||
├── Revenue down
|
||
│ ├── Volume down
|
||
│ │ ├── Fewer customers
|
||
│ │ └── Less per customer
|
||
│ └── Price down
|
||
│ ├── Discounts up
|
||
│ └── Mix shift to cheaper SKUs
|
||
└── Costs up
|
||
├── COGS up (input price, supplier, waste)
|
||
└── SG&A up (headcount, marketing, IT)
|
||
```
|
||
|
||
### Hypothesis tree
|
||
```
|
||
Root hypothesis: "Profit decline is driven by margin compression in Region A."
|
||
├── H1: input costs in A rose >5% YoY [test: supplier invoices]
|
||
├── H2: A introduced discounting in Q3 [test: pricing data]
|
||
└── H3: A's mix shifted to low-margin SKUs [test: SKU-level P&L]
|
||
```
|
||
|
||
### Profit decomposition
|
||
```
|
||
Profit = (Price - VariableCost) × Quantity - FixedCost
|
||
↓ each is a lever; trace YoY delta to isolate cause
|
||
```
|
||
|
||
### Market sizing (top-down)
|
||
```
|
||
US coffee shop market size:
|
||
≈ 330M people
|
||
× 60% coffee drinkers
|
||
× 250 cups/year average
|
||
× $4 average cup
|
||
≈ $198B (sanity-check vs $100B reported → adjust assumptions)
|
||
```
|
||
|
||
### Data-interp checklist (PST-style)
|
||
1. Read title + axes + units first.
|
||
2. What is the question actually asking?
|
||
3. Eliminate clearly wrong options (often 2 quickly).
|
||
4. Compute only what's needed (not all entries).
|
||
5. Beware base-rate fallacy: % vs absolute.
|
||
|
||
### Hypothesis-driven case interview opening
|
||
```
|
||
"Before diving in, I'd like to structure my thinking.
|
||
Given the goal is [restate], I see three areas to explore:
|
||
1. ... 2. ... 3. ... [MECE check]
|
||
I hypothesize the answer lies in [#2] because [reason].
|
||
I'd like to start by asking about [data needed to test #2].
|
||
Does that approach work?"
|
||
```
|
||
|
||
### Quick math drills (PST training)
|
||
```
|
||
- Mental %: 17% of 240 → 10% (24) + 5% (12) + 2% (4.8) ≈ 40.8
|
||
- Growth: $100 → $150 over 5 yrs → 1.5^(1/5) ≈ 1.085 ≈ 8.5% CAGR
|
||
- Breakeven: FC / (P - VC)
|
||
- Return on investment: ΔProfit / Investment
|
||
```
|
||
|
||
## 매 결정 기준
|
||
| 상황 | Approach |
|
||
|---|---|
|
||
| Preparing for McKinsey 2026 | Practice Solve (game), not legacy PST |
|
||
| BCG / Bain interview | Online case + structured case method |
|
||
| Improve general problem-solving | MECE + hypothesis tree drills |
|
||
| Ambiguous business problem | Issue tree → 80/20 → hypothesis test |
|
||
| Quantitative case (sizing) | Top-down + bottom-up cross-check |
|
||
|
||
**기본값**: MECE issue tree → hypothesize → data → synthesize. Format-agnostic.
|
||
|
||
## 🔗 Graph
|
||
- 부모: [[Problem_Solving|Problem-Solving]]
|
||
- 변형: [[McKinsey-Solve]] · [[Case-Interview]]
|
||
- 응용: [[Strategy-Consulting]]
|
||
- Adjacent: [[MECE]] · [[Hypothesis-Tree]] · [[Pareto-Principle]]
|
||
|
||
## 🤖 LLM 활용
|
||
**언제**: structured business analysis, case interview prep, strategic decomposition of ambiguous problems.
|
||
**언제 X**: technical engineering decisions (use systems thinking instead), pure math optimization.
|
||
|
||
## ❌ 안티패턴
|
||
- **Boiling the ocean**: not 80/20 — analyze every branch equally.
|
||
- **Non-MECE buckets**: overlapping or missing categories.
|
||
- **Hypothesis without test**: "I think X" w/ no falsification plan.
|
||
- **Data dump**: charts without "so what".
|
||
- **Memorizing PST questions**: format is gone since 2019.
|
||
|
||
## 🧪 검증 / 중복
|
||
- Verified (McKinsey careers website, Minto Pyramid Principle, Case in Point textbook).
|
||
- 신뢰도 A.
|
||
|
||
## 🕓 Changelog
|
||
| 날짜 | 변경 |
|
||
|---|---|
|
||
| 2026-05-08 | Phase 1 |
|
||
| 2026-05-10 | Manual cleanup — PST history + transferable structured thinking skills |
|