McKinsey PST: what it was, how it worked, and what replaced it

What was the McKinsey PST?

The McKinsey Problem Solving Test (PST) was a written case exam that McKinsey used for more than a decade to screen applicants before case interviews. Candidates sat in a room with a test booklet, scratch paper and a pencil, and worked through business cases presented as short text passages, charts and tables.

Each case described a fictional client: a retailer, a manufacturer, a government agency, a restaurant. The client had a problem, and every question asked you to take one analytical step toward solving it. One question might ask which factor best explains a decline in profit. The next might ask you to calculate the payback period of an investment from a table.

I took the PST myself and later coached candidates through it. It was a fair test. It rewarded people who read precisely and calculated calmly, and it punished people who skimmed.

The PST format at a glance

The format stayed stable for years, which made it one of the most predictable steps in consulting recruiting.

Some offices reportedly gave non-native English speakers extra time. Candidates who asked their recruiter in advance usually got a clear answer.

The three question types

Almost every PST question fell into one of three families. Knowing them let you recognize what was being asked within seconds.

1. Reasoning questions. "Which of the following statements, if true, best supports the client's hypothesis?" These tested whether you could separate a valid conclusion from a plausible-sounding one.
2. Calculation questions. "By how much would annual profit change if the client switched suppliers?" These required pulling two or three numbers from an exhibit and doing clean arithmetic by hand.
3. Data interpretation questions. "Which conclusion can be drawn from Exhibit 2?" These tested chart reading: axes, units, percentages versus absolute values.

Many candidates lost points on the first type. They picked the statement that was true in general instead of the one that answered the client's specific question. I cover that trap in detail in how to beat a written case test.

Where the PST sat in the McKinsey funnel

The PST was the second filter. McKinsey first screened resumes and cover letters, then invited a share of applicants to the test, then invited those who passed to a first round of case interviews.

In my original estimates, about two out of three applicants were rejected at the resume stage, and roughly two out of three PST takers failed the test. That made the PST the single biggest elimination step after the resume screen. For the full funnel numbers, then and now, see how many candidates pass.

A strong score could also help later. Interviewers sometimes saw the result, and a near-perfect test gave a candidate some credit going into the first round.

Why McKinsey retired the PST

Paper tests were expensive to run. Every sitting required a room, a proctor and printed booklets, and the format had leaked widely: practice tests and old versions circulated among students for years. McKinsey also wanted a measure of how candidates work, beyond whether they pick the right letter.

Prep providers describe Solve as replacing older pen-and-paper aptitude tests that were costly to administer. The switch happened office by office over several years, and today the PST appears only in historical accounts.

What replaced it: McKinsey Solve

McKinsey now uses Solve, which it describes as a gamified assessment that tests problem solving. Candidates take it online, alone, and may not use apps, websites, AI tools or pre-prepared notes.

Candidate reports for 2026 describe two common versions:

• About 65 minutes: Redrock Study (about 35 minutes) and Sea Wolf (about 30 minutes).
• About 85 minutes: the same two games plus Sustainable Futures Lab (about 20 minutes), rolled out from around March 2026.

According to prep providers, Solve scores both your final answers (a "product" score) and how you reached them (a "process" score). McKinsey does not publish a cutoff. For the full breakdown of the games and rules, read the McKinsey test in 2026.

Stephan's note: The skills the PST tested carry straight into Solve. Every Solve game still asks you to read a body of information, find the numbers that matter, calculate accurately and decide. Candidates who trained for the PST had that habit drilled in.

What PST preparation still teaches

The PST trained three habits that remain valuable for Solve, for written cases at other firms, and for live case interviews.

• Reading for the question. Read the question before the passage, then hunt for the data that answers it.
• Calculator-free math. Percentages, growth rates, break-even and payback, done accurately in your head or on paper. My case interview math guide covers the shortcuts.
• Finding the client's real objective. The best answer serves what the client is trying to achieve, which is often one level above what they literally asked.

Some firms and some recruiting tracks still use written case exercises, and most final rounds include data-heavy cases. A full timed practice test remains one of the most efficient ways to build these habits. The Key to the PST is a 26-question practice test in the original PST format, with a complete answer guide that explains the reasoning behind every option. Use it as a timed drill for exhibit reading and mental math, knowing that the PST itself is retired. You can find it on the Key to the PST page.

How to use this page

If you arrived here because an older guide told you to prepare for the PST, update your plan. Start with what Solve looks like today, then add a short block of written case and math practice to sharpen the underlying skills. A 4-week practice plan shows how to fit both into a month.