What 8,600 certification practice questions actually look like
Every article about exam preparation quotes the awarding body's published outline. This one
reports the other side: what a corpus of questions written to those outlines is actually
made of. The figures below are computed from CertCrafter's entire question bank —
8,600 questions across 10 professional certifications —
not a sample.
Last computed , automatically at build
The corpus in brief
Questions
8,600
Certifications
10
Full-length tests
58
Blueprint domains covered
66
Mean stem length
52 words
Explanation coverage
100%
How long is a typical practice question?
The mean stem across the whole corpus is 52 words, but that average hides
the most interesting finding here: stem length is a property of the exam, not of the writer. A
scenario-led exam forces long stems because the scenario is the question; a recall exam cannot
support them. The spread below runs from 25 to
130 words — a factor of
5.
How are questions spread across blueprint domains?
Awarding bodies differ sharply in how much they tell you. Some publish percentage weights per
domain; several of these publish none at all, in which case the distribution below is the
author's estimate anchored to the exam's structure and should never be attributed to the body.
The count of domains alone is informative: it ranges from
3 to 13.
PMP 2026 Exam Update: New ECO
Domain
Questions
Share
Domain II: Process
492
41%
Domain I: People
396
33%
Domain III: Business Environment
312
26%
API 510 Pressure Vessel Inspector
Domain
Questions
Share
IV. Practical Knowledge - General
660
64.7%
I. Thickness Measurements, Inspection Intervals and Vessel Integrity
120
11.8%
V. Practical Knowledge - Specific
90
8.8%
III. Nondestructive Examination
78
7.6%
II. Welding Procedure and Qualification Evaluation
72
7.1%
API 653 Aboveground Storage Tank Inspector
Domain
Questions
Share
IV. Practical Knowledge - General
456
44.7%
I. Calculations & Tabular Evaluations for Evaluating Thickness Measurements, Weld Sizes, and Tank Integrity
276
27.1%
II. Welding on Atmospheric Aboveground Storage Tanks
120
11.8%
V. Practical Knowledge - Specific
84
8.2%
III. Nondestructive Examination
84
8.2%
ASME GDTP Technologist: Y14.5-2018
Domain
Questions
Share
Sections 3-6: Definitions, Rules, Tolerancing and Symbology
228
25.3%
Section 10: Tolerances of Location (Position)
222
24.7%
Section 7: Datums and Datum Reference Frames
180
20%
Section 11: Tolerances of Profile
138
15.3%
Section 9: Tolerances of Orientation
48
5.3%
Section 8: Tolerances of Form
42
4.7%
Section 12: Tolerances of Runout
42
4.7%
ASNT NDT Level II: Ultrasonic Testing
Domain
Questions
Share
Equipment, Transducers and Calibration
192
21.3%
Techniques: Straight Beam, Angle Beam and Specialised Methods
180
20%
UT Physics and Wave Propagation
180
20%
Examination of Materials, Product Forms and Weldments
150
16.7%
Data Collection, Interpretation, Evaluation and Reporting
138
15.3%
Codes, Standards, Procedures, Certification and Safety
60
6.7%
ASQ Certified Reliability Engineer
Domain
Questions
Share
IV. Reliability Planning, Testing, and Modeling
210
23.3%
III. Probability and Statistics for Reliability
210
23.3%
I. Reliability Fundamentals
174
19.3%
V. Lifecycle Reliability
156
17.3%
II. Risk Management
150
16.7%
NEBOSH International General Certificate: 2025 Specification
Domain
Questions
Share
GIC1 Element 3: Managing risk - understanding people and processes
156
17.3%
GIC2 Element 8: General workplace issues
108
12%
GIC2 Practical: Workplace risk assessment (template Parts 1-4)
90
10%
GIC1 Element 4: Health and safety monitoring and measuring
84
9.3%
GIC2 Element 5: Physical and psychological health
84
9.3%
GIC2 Element 7: Chemical and biological agents
72
8%
GIC2 Element 6: Musculoskeletal health
66
7.3%
GIC1 Element 2: How health and safety management systems work and what they look like
60
6.7%
GIC1 Element 1: Why we should manage workplace health and safety
60
6.7%
GIC2 Element 9: Work equipment
60
6.7%
GIC2 Element 10: Fire
36
4%
GIC2 Element 11: Electricity
24
2.7%
LPIC-3 305-300: Virtualization and Containerization
Domain
Questions
Share
352.3 Docker
108
15%
351.4 Libvirt Virtual Machine Management
108
15%
352.1 Container Virtualization Concepts
84
11.7%
352.2 LXC
72
10%
351.1 Virtualization Concepts and Theory
72
10%
351.3 QEMU
48
6.7%
353.4 Vagrant
36
5%
351.2 Xen
36
5%
352.4 Container Orchestration Platforms
36
5%
353.3 cloud-init
36
5%
351.5 Virtual Machine Disk Image Management
36
5%
353.1 Cloud Management Tools
24
3.3%
353.2 Packer
24
3.3%
API 570 Piping Inspector
Domain
Questions
Share
IV. Practical Knowledge - General
440
64.7%
I. Calculations for Evaluating Thickness Measurements, Inspection Intervals, and Piping Integrity
80
11.8%
V. Practical Knowledge - Specific
60
8.8%
III. Nondestructive Examination
52
7.6%
II. Welding Procedure and Qualification Evaluation
48
7.1%
MB-330: Dynamics 365 Supply Chain Management
Domain
Questions
Share
Implement product information management
96
26.7%
Implement inventory and asset management
84
23.3%
Implement warehouse management and transportation management
78
21.7%
Implement and manage supply chain processes
60
16.7%
Implement master planning
42
11.7%
Which exams split into open-book and closed-book?
Three of these certifications are sat in two sittings, one with the reference documents on
screen and one without, and the practice banks mirror that split question by question rather
than shuffling them together. 960 questions across the corpus are marked
open-book — every one of them in an API inspection exam.
Certification
Open-book questions
Share of bank
API 510 Pressure Vessel Inspector
360
35.3%
API 653 Aboveground Storage Tank Inspector
360
35.3%
API 570 Piping Inspector
240
35.3%
How many questions allow more than one answer?
198 of 8,600 questions are multi-select. They cluster
almost entirely in the IT exams, where selecting exactly the right set of commands or settings
is the skill being tested, and are absent from the inspection and safety exams where the format
is single-answer throughout.
Questions people ask about this data
Where do these numbers come from?
They are computed at build time from CertCrafter's own 8,600 practice questions — the same files a customer receives. Nothing is sampled or estimated: every figure counts the whole corpus. No question text is published here, only structure.
How long is a typical certification practice question?
Across 8,600 questions the mean stem is 52 words. That varies enormously by exam: scenario-led exams like PMP run far longer than command-recall exams like LPIC-3, which is a fact about the exams rather than about the writing.
What share of questions carry a written explanation?
100% of questions have an explanation covering why the correct answer is correct and why each distractor is wrong. Explanation coverage is the single biggest difference between a practice bank you learn from and one you merely score against.
May I cite this?
Yes. The figures are published under CC BY 4.0 — use them with a link back to this page. If you want a cut we have not published, ask and we will run it.
Method and licence
How this was produced
Computed automatically at every build by src/lib/bankStats.ts, reading the same
question files a customer receives. No sampling, no estimation, no rounding beyond one
decimal place. The figures change when the banks change.
No question text, answer option or explanation is published here — only
counts and distributions. The aggregate is publishable precisely because it is not the product.
Free to cite under CC BY 4.0
with a link to this page. Want a cut we have not published — length by domain, distractor
patterns, anything else? Ask and we will run it.