About
About Quant90
Free lessons and original practice for the Quant section of the GMAT™ exam (Focus Edition), written to the difficulty of the real test.
What it is
Quant90 teaches the Quant section one topic at a time and lets you practice it under test conditions. There are 16 topics, 82 lessons, 156 practice questions and 200 topic-quiz questions, a full 21-question, 45-minute adaptive section, and a readiness estimate that turns your answers into a likely Quant score.
As on the real section, every question is Problem Solving and none needs a calculator. The site is free, with no account and no ads.
Each lesson has eight parts: the idea in plain words, why it works, worked examples from Core up, common traps, shortcuts without a calculator, a quick check, a formula card and practice. Every explanation names the slip behind each wrong answer, so a miss tells you what to fix.
Who it is for
People preparing for the exam who want practice at the level of the real test, or harder. Every question has one of four levels, each with a target time:
| Level | About this total score | Target time |
|---|---|---|
| Core | 605 to 655 | 1:45 |
| Hard | 655 to 705 | 2:15 |
| Very hard | 705 to 805 | 3:00 |
| Beyond | harder than the test | 3:30 |
The bands are on the total-score scale (205 to 805). They are our judgment of where a question sits, not GMAC’s. On the full section the clock allows about 2:09 a question, so the targets are a pace to aim for, not a limit.
How the questions are made original
Every lesson, worked example and question on the site was written from scratch for Quant90. None is copied, adapted or reworded from official guides, other test-prep companies, forums or math contests. The numbers, the settings and the wrong answers are our own.
The topic-quiz questions are written apart from the practice questions and never appear in the lessons or practice sets (the full section can draw on them). The content check flags any quiz question whose wording matches another question on the site.
How they are checked
- Each answer is worked out and then checked by putting it back into the question. Nearly every explanation ends with that check, so you can follow it.
- From the Hard level up, each explanation shows a fast route and a reliable backup, and says when to switch.
- An automated content check reads every file before it goes on the site: exactly five choices, an answer key that points to one of them, no two choices the same, a note and a mistake tag for every wrong choice, well-formed math notation and a level for every question.
- In each topic quiz the correct letters are spread out: every letter from A to E is the answer somewhere, and none is the answer to more than 40% of the questions.
Careful writing and automated checks can still miss a slip now and then. Each explanation shows every step, so if an answer looks wrong to you, you can see exactly where you and the explanation part ways.
The score estimate
The readiness estimate on the dashboard, and the score shown after a full section, are practice estimates, not official scores.
In short: each question’s difficulty comes from its level. Your first try at each question moves an ability rating for its topic; a right answer on a hard question counts for more, and a miss on an easy one costs more. The dashboard then plays out 2,000 adaptive 21-question sections on a 45-minute clock at your own pace, and turns each result into a score from 60 to 90 with GMAC’s published Quant percentiles. The middle result is the estimate, and eight in ten of the results fall inside the range shown. A full section is scored the same way from its 21 answers.
Source: GMAC, GMAT™ Score Concordance Table, Quantitative Reasoning Score Sorted by Percentile (published Aug. 2026; test takers July 1, 2021 to June 30, 2026), on gmac.com.
We tested the method on simulated students, and those students follow the method’s own assumptions. How close it comes for real test takers is not known yet, so treat the number as a guide to your progress, not a prediction you can count on.
Trademarks
GMAT™ is a registered trademark of the Graduate Management Admission Council™ (GMAC™). Quant90 is an independent site. It is not affiliated with or endorsed by GMAC, and it uses no GMAC questions.