LEK Numerical Reasoning Test 2026: 18 Questions, 30 Min Guide

Last Updated on May 21, 2026

Updated May 2026 · By Florian Smeritschnig, Former McKinsey Senior Consultant

The LEK Numerical Reasoning Test (also called the LEK Aptitude Test or LEK Consulting Aptitude Test) is an 18-question, 30-minute Zoom-proctored numerical and logical reasoning assessment that L.E.K. Consulting uses as a pre-interview screen for Associate and Consultant candidates. The math content is GCSE / GMAT-style (no calculator allowed), the question types cover six distinct categories (fast math, critical reasoning, data interpretation, basic algebra, data sufficiency, error spotting), and difficulty escalates sharply after questions 14-16. Below is the full format breakdown, the six question types with sample patterns, the preparation strategy that actually works at this time pressure, and how the LEK test compares to BCG Cognitive Test, Bain SOVA, and other consulting aptitude assessments.

After 5 years at McKinsey and coaching hundreds of candidates through Tier-2 strategy recruiting (including LEK specifically), I can tell you exactly how the LEK Numerical Reasoning Test differs from broader GMAT/GRE preparation, which question types reliably trip up candidates, and the pacing strategy that lifts most candidates from “completed 12 of 18” to “completed 16 of 18 at 85%+ accuracy.”

Key Takeaways

• 18 questions in 30 minutes = ~100 seconds per question average
• Zoom-proctored online with camera-on supervision
• No calculator allowed; pen and paper only
• Six question types: fast math, critical reasoning, data interpretation, basic algebra, data sufficiency, error spotting
• Difficulty escalates sharply after questions 14-16, strategic skipping is essential
• GMAT-style content but with shorter per-question time budget than GMAT
• Used at the LEK Associate / Consultant screening stage before case interviews

Test Format at a Glance

These details reflect the test’s standard format across recent L.E.K. recruiting cycles. LEK does not publicly publish the test specifications, but format details are consistent across regional offices.

What the LEK Test Actually Evaluates

LEK Consulting’s screening tool measures three capabilities under time pressure:

1. Mental math speed. The test deliberately prohibits calculators to force candidates to demonstrate the kind of quick arithmetic and approximation that real consulting work requires. A consultant in a client meeting estimates margins, market sizes, and growth rates in real time, the LEK test screens for that capacity.

2. Quantitative reasoning under structured constraints. Beyond arithmetic, the test evaluates whether candidates can extract relevant information from charts, tables, and word problems, then apply algebraic logic to reach defensible answers.

3. Pacing discipline and prioritization. The 18-questions-in-30-minutes structure plus the escalating difficulty curve creates a self-selection mechanism: candidates who refuse to skip difficult questions fail to complete the test; candidates who skip too aggressively fail to demonstrate enough accuracy. Strategic prioritization is the test’s hidden third evaluation criterion.

The Six Question Types (With Sample Patterns)

The 18 questions distribute across six content domains. Counts vary slightly by test version, but the rough distribution is consistent.

1. Fast Math (4-5 questions)

Pure mental arithmetic under time pressure. Multiplication, division, percentages, ratios.

Sample pattern: “What is 14% of 3,250?”

• Strong answer: 14% ≈ 1/7. 3,250 / 7 ≈ 464. Refine: actual answer 455.
• The point is approximation skill, not exact precision, when 4-second answers are needed.

Drill recommendation: Build automatic multiplication tables through 15×15 with sub-1-second recall, and percentage-of rules (10%, 15%, 20%, 25%) by direct mental conversion.

2. Critical Reasoning (3-4 questions)

Logic problems requiring deductive inference from given premises.

Sample pattern: “If all consultants at firm X work at least one client engagement, and the average consultant works 1.8 engagements per year, what is the minimum percentage of consultants who work more than one engagement?”

• This requires recognizing the constraint and solving algebraically (or by approximation).

Drill recommendation: GMAT Critical Reasoning section and logic puzzle practice. The pattern is similar but the LEK time pressure is tighter. For free GMAT prep resources, see here: Critical reasoning practice for the GMAT, Quantitative practice for the GMAT.

3. Data Interpretation from Tables and Charts (3-4 questions)

Extract information from visual data, then perform calculations.

Sample pattern: A bar chart shows revenue by region across 4 regions. A second chart shows margin by region. The question asks: “Which region contributes the most absolute gross profit?”

• Requires combining two charts, multiplying revenue × margin per region, and comparing.

Drill recommendation: GMAT Integrated Reasoning section, plus practicing with real consulting deck exhibits. The chart interpretation drills cover the format directly.

4. Basic Algebra (3-4 questions)

Word problems requiring algebraic setup, then solution.

Sample pattern: “A company has 3 product lines. Line A has 40% of revenue. Line B has $80M. The total revenue is twice Line C’s revenue. What is Line C’s revenue?”

• Requires setting up equations from the word problem and solving.

Drill recommendation: GMAT Quantitative section, particularly word problems. Manhattan Prep’s GMAT word problem book is one of the better external resources.

5. Data Sufficiency (2-3 questions)

A question is given along with two statements. Determine whether the statements together, separately, or not at all provide sufficient information to answer.

Sample pattern: “Question: What is the average revenue per customer at Company X? Statement 1: Total revenue is $50M. Statement 2: There are 5,000 customers.”

• The right answer here: both statements together are sufficient; neither alone is sufficient.

Drill recommendation: GMAT Data Sufficiency section. This is the question type most candidates underprepare for because it doesn’t exist in standard tests like SAT/ACT.

6. Error Spotting (1-2 questions)

Identify computational errors in a worked solution presented in the question.

Sample pattern: A multi-step financial calculation is shown with the final answer. Identify which step contains an arithmetic error.

Drill recommendation: Practice by reviewing your own past case interview math and chart calculations, looking for where you would have caught your own arithmetic errors.

Why the Difficulty Curve Matters

The single most important insight about the LEK test: questions 1-13 are meaningfully easier than questions 14-18.

This is not subtle. Candidates who race through the first 13 questions and arrive at question 14 with 18 minutes remaining find that the remaining 5 questions require 8-12 minutes each rather than the average 100 seconds. Many candidates fail the test not because they can’t solve the difficult questions, but because they didn’t budget enough time to attempt them.

The practical implication: target completing questions 1-13 in 16-18 minutes, leaving 12-14 minutes for questions 14-18. This requires more aggressive pacing than candidates naturally apply.

The corollary: skipping is required. If question 6 takes you 4 minutes despite being a “medium” question, abandon it and move on. Returning later is allowed (unlike some other consulting tests), so you can come back if time permits.

How to Prepare for the LEK Numerical Reasoning Test

The right preparation arc has four phases, totaling 8 to 15 hours for most candidates.

Phase 1: Diagnostic (1-2 hours)

Take a timed 18-question practice set under realistic conditions. Use GMAT quantitative practice questions as a proxy (the LEK test does not have public official practice tests).

Record three numbers: how many you completed in 30 minutes, your accuracy on completed questions, and which question types slowed you down most. This gives you the baseline to optimize against.

Most candidates’ first attempt: 12-15 completed, 65-80% accuracy on completed. Target after preparation: 16-18 completed, 85%+ accuracy.

Phase 2: Build Mental Math Speed (4-6 hours)

You need mental math to be reflexive. Specifically:

• Multiplication tables through 15 × 15 with sub-1-second recall
• Percentage rules (10%, 12.5%, 15%, 20%, 25%, 33%, 50%) by instant conversion
• Common decimal-fraction equivalents (1/3 ≈ 0.333, 1/6 ≈ 0.167, 1/7 ≈ 0.143, 1/8 = 0.125, 1/9 ≈ 0.111)
• Quick approximation for division (is 47/213 closer to 20% or 25%?)
• Powers of 10 navigation for large numbers (4.5 × 10^8 ÷ 9 × 10^4)

The case interview math drills build this baseline systematically. Most candidates need 5-10 hours of pure math drilling before LEK practice tests become useful.

Phase 3: Question-Type-Specific Drilling (3-5 hours)

Allocate time across the six question types proportional to how heavily they appear (fast math and basic algebra get the most; error spotting gets the least). Use GMAT-style practice questions for each type:

• Manhattan Prep GMAT Quantitative materials
• GMAT Official Guide
• Free GMAT practice from manhattanreview.com or other reputable sources
• Data Sufficiency requires specific practice, most candidates underdrill this

Phase 4: Full-Length Timed Simulation (1-2 hours, final week before test)

In your final week, run at least one full-length 30-minute simulation under realistic conditions. Camera on, room set up the way it will be during the actual proctored session, no distractions. Force yourself to skip ruthlessly using a 100-second mental timer per question.

This is the practice session that builds the pacing discipline. Without it, the actual test feels significantly harder than expected.

LEK Test vs Other Consulting Aptitude Tests

The LEK Numerical Reasoning Test sits within the broader family of consulting aptitude assessments. Quick comparison:

Key differences for LEK candidates:

• vs BCG Cognitive Test: LEK has fewer questions (18 vs 80) with more time per question (100s vs 22s). LEK is more about deep reasoning; BCG is about speed under extreme time pressure. See the BCG Cognitive Test guide.
• vs Bain SOVA: LEK is purely numerical/logical; SOVA includes verbal and situational components. See the Bain SOVA test guide.
• vs McKinsey Solve: LEK is traditional test format; McKinsey Solve is game-based ecology simulation. Different skill sets.
• vs Kearney: Most similar test in format and difficulty. Preparation overlaps significantly. See the Kearney Recruitment Test guide.

Candidates preparing for the LEK test who are also recruiting at other Tier-2 strategy firms (Strategy&, Roland Berger, Oliver Wyman, Kearney) get high marginal return from the preparation since the underlying skills transfer directly.

Virtual Test-Taking: Logistics Matter

The LEK test is administered via Zoom with a proctor watching your camera throughout. The proctoring is standard but the logistics setup affects performance.

Pre-test checklist (the night before):

• Stable internet connection (wired Ethernet preferred over Wi-Fi if possible)
• Test your camera, microphone, and Zoom client
• Charge your laptop or have it plugged in
• Clear your desk; no books, devices, or papers other than blank scratch paper
• Print or ready 4-6 sheets of blank paper plus 2-3 working pens
• Phone face-down or in another room

Test day:

• Eat a real meal 60-90 minutes before; avoid heavy caffeine that crashes mid-test
• Log in 5-10 minutes early
• Inform household members or anyone in the space not to interrupt
• Have a glass of water ready (allowed during the test)

During the test:

• Camera stays on; look at the screen, not off-screen
• Take scratch notes for math; mental math errors compound at this time pressure
• If you finish early, review your most uncertain answers; the test allows revision

Common voiding triggers:

• Looking off-screen for more than a few seconds
• A second device in view
• Anyone else in the room
• Internet disconnect mid-test (some proctors allow a retry; others don’t)

Common Mistakes Candidates Make

After coaching hundreds of candidates through consulting tests, the patterns that cost their progress in the recruiting journey:

1. Spending too long on early questions. Questions 1-5 are deliberately easier to build confidence. Candidates who take 3-4 minutes on each “to make sure” arrive at question 14 with 12 minutes remaining and run out of time on the difficult questions. Target 1-2 minutes for the early questions.

2. Treating it like a GMAT. GMAT allows 2 minutes per question and has higher information density per question. LEK has 100 seconds per question on average and rewards aggressive approximation more. GMAT preparation is useful for content but the pacing instincts need calibration.

3. Refusing to skip. Sunk-cost instinct kicks in around the 90-second mark on a difficult question. Override it. The test allows revision; you can come back. Skipping is a feature, not a failure.

4. Underestimating Data Sufficiency. Most candidates have never encountered this format outside of GMAT. The 2-3 Data Sufficiency questions on the LEK test trip up unprepared candidates disproportionately. Drill this question type specifically.

5. Not building mental math automaticity. Candidates who can calculate but slowly fail the LEK test even with strong math content knowledge. The test screens for speed of basic operations. Multiplication tables and percentage rules need to be automatic, not calculated.

6. Poor test-day logistics. Slow internet, distractions, no scratch paper, missing the start time, these failures account for roughly 10-15% of LEK test failures. Avoidable.

7. No full-length simulation before the actual test. Practicing individual question types is not the same as running 18 questions in 30 minutes back-to-back with proctored conditions. The cognitive load of the proctored environment plus full-length pacing is different from drill practice.

Frequently Asked Questions

The Bottom Line

The LEK Numerical Reasoning Test is one of the more demanding Tier-2 strategy consulting aptitude tests because it combines genuine quantitative depth with sharp time pressure. Most candidates who fail the LEK test did not fail on math knowledge, they failed on pacing discipline and on underpreparation for Data Sufficiency specifically.

The right preparation path: diagnose your baseline with one timed simulation, build mental math automaticity through 5-10 hours of focused drilling, work through question-type-specific GMAT practice, and run at least one full-length proctored simulation in your final week. Total prep time: 8-15 hours for most candidates.

For systematic mental math speed building, the case interview math drills cover the underlying numerical fluency needed for the LEK test plus the case interviews that follow. For the broader case interview preparation including structuring, chart interpretation, and case math, and case communication that LEK uses in subsequent rounds, the Case Interview Academy covers the full curriculum.

If you want a calibrated review of your specific LEK preparation, plus a customized plan for the full LEK recruiting cycle (test + case interviews + fit rounds), book a 1-on-1 coaching session. The test is hard, but it is consistent: candidates who prepare specifically for the pacing and question-type mix pass at a much higher rate than candidates who treat it as a generic GMAT clone.