Learn how the 35-minute Redrock Study works, master its four phases, and prepare with detailed strategy, maths guidance, and realistic practice.
Last updated: September 2026
McKinsey Solve walkthrough
McKinsey Redrock is a 35-minute interactive case study in the McKinsey Solve assessment. It presents a scenario, typically involving ecosystem dynamics on a fictional island, where you gather information, perform calculations, and deliver recommendations.
You may also see it called Redrock Island, Redrock Study, or the Red Rock case study. These names describe the same module.
Redrock is 35 minutes and is commonly completed in the same sitting as Sea Wolf, which lasts 30 minutes. A 65-minute invitation commonly refers to those two modules. An 85-minute invitation usually adds the established Sustainable Futures Lab format, while some 95-minute invitations appear to include a tested longer SFL format.
Your own invitation is the authority for the modules and timing you will receive. Read the McKinsey Solve Game overview for the complete assessment sequence.
McKinsey Redrock follows four sequential phases in one 35-minute sitting. The Report phase creates the most important navigation constraint: once it starts, you cannot return to your Investigation or Analysis work.
Phase 1
Roughly 8–12 minutes
You meet the case through a narrative scenario about ecological research on Red Rock Island, with exhibits such as tables, charts, and species data. The task is not to read everything; it is to decide which facts you will need later and park them in the research journal.
You can still open Investigation from Analysis if you need to verify an exhibit. That access ends when Report begins.
Phase 2
Roughly 10–15 minutes
You answer a short set of quantitative questions, typically three, that depend on the evidence you captured. The on-screen calculator is part of the workflow; journal entries can be referenced while you work.
Return to Investigation if an exhibit detail is missing from your journal, but finish that review before you enter Report.
Phase 3
Roughly 8–12 minutes
You synthesise earlier work into two deliverables: a written summary and a visual report. This phase tests whether you can state conclusions clearly and match numbers to the right chart format.
This is the main navigation constraint in Redrock. Capture anything you might need in the journal before you click forward from Analysis.
Phase 4
Roughly 10–15 minutes
Six standalone quantitative questions close the module. They do not reference the island scenario. Each item is its own mini-problem while the same 35-minute timer keeps running.
Cases reward fluency with fundamentals more than recall from the main case. Refresh core maths before test day so execution stays automatic.
Many candidates find the time pressure challenging, but the mathematical concepts themselves are accessible. Confidence with these fundamentals is essential because the calculations need to feel automatic while the timer is running.
Although a calculator is provided, mental arithmetic remains important for quick verification. Being able to spot an answer that is an order of magnitude off prevents costly mistakes.
Percentage calculations appear frequently. Make sure you can apply changes, recover original values, and recognise when successive percentages must be multiplied.
Be comfortable calculating and interpreting mean, median, and mode, including from histograms. A common error is identifying the median as the middle value on the x-axis rather than the middle value in the ordered dataset.
Quick mental estimates help catch calculator errors. For instance, 23% of 250 should be close to 25% of 250, which is 62.5. If the calculator shows 575, something went wrong.
Time pressure is more challenging than the underlying mathematics. The strongest approach keeps your evidence organised, your calculations easy to verify, and your pace steady enough to reach every phase without rushing the final questions.
The on-screen calculator and interactive journal are part of the assessment workflow. Use the calculator for non-trivial arithmetic. Organise the journal thoughtfully, rename generic labels, group related information, and highlight critical values.
There is no penalty for incorrect answers, so leaving a question blank only guarantees zero points. When time is short or uncertainty is high, make a reasoned choice and move forward.
Build a brief review window, even 10 seconds, before confirming each answer. Check the unit, sign, decimal place, and requested answer format before you commit.
Question wording can be unclear. Spending excessive time trying to decode the perfect interpretation is counterproductive. Make a reasonable interpretation, commit to it, and proceed.
Questions that appear sequential may actually be independent. A follow-up can introduce a temporary assumption or return to the original baseline, so read each question on its own terms.
Baseline: the elk population is always three times the bear population, elk grow 8% annually, and Year 1 elk equal 120.
The trap is carrying the temporary 15% assumption into a question that has returned to the baseline.
A few focused practice sessions are more valuable than hours of passive research. Use this sequence to make the calculations, interface, and test flow feel familiar before test day.
If percentage calculations, probability concepts, or statistical measures feel unfamiliar, invest time in targeted practice. The goal is not advanced mathematical mastery; it is fluency with the basics so execution becomes automatic.
Learn when you can return to earlier work and when the Report phase locks it. After a walkthrough, the structure becomes familiar and less intimidating; extensive passive video research offers diminishing returns beyond basic orientation.
Work through simulations that replicate the interface, timing, and question complexity. A good practice case should feel challenging and somewhat ambiguous because that is the experience you need to rehearse.
For a closer look at the tools themselves, read the Redrock calculator and interface guide.
The Redrock case library covers the complete four-phase workflow under timed conditions. Practise with interactive exhibits, the journal system, and the same transition into written and visual reporting that you need to manage in the assessment.
Clear answers about the format, preparation, and names you may see before test day.
The Redrock game (also called Red Rock Study or Redrock Island) is a data-focused case study within McKinsey's digital assessment. Candidates analyse information about a fictional ecosystem and work through research, analysis, and reporting phases to demonstrate structured thinking and quantitative skills.
Yes. Redrock Island describes the setting, while Redrock Study describes the task. Both names refer to the same four-phase case inside McKinsey Solve.
Redrock lasts 35 minutes and must be completed in one sitting. Your invitation will show which other Solve modules are included in your assessment.
The challenge comes primarily from time pressure rather than mathematical complexity. Candidates who have practised with realistic simulations and are comfortable with percentage calculations, probability, and data interpretation generally find it manageable.
Complete practice cases that simulate the real format, including the interface, timing, and question style. Supplement this with targeted review of any mathematical concepts that feel rusty. A few quality practice sessions are more valuable than passive study.
McKinsey offers limited preview information but not a full practice version of the Redrock assessment. Third-party simulators based on candidate research provide the closest approximation to the real experience.
Yes. Solve Games Guide includes one free Redrock case with the same Investigation, Analysis, Report, and Cases flow. No credit card is required.
Strong quantitative skills improve baseline performance, but the Redrock interface is unfamiliar to most candidates. Practising with a simulator removes the cognitive overhead of learning the format during the actual assessment.
The Solve assessment, including Redrock, is an early screening stage. Performance influences whether candidates advance to interviews. McKinsey does not typically share specific scores.
Policies vary, but candidates typically cannot retake Solve for the same role within approximately 12 months. It is best to prepare thoroughly for the first attempt and confirm the current policy with your recruiter.
Select the package that fits your preparation needs. All packages include 2-week access.
You only get one attempt at the McKinsey Solve Games. This costs less than a single interview coaching session, and prepares you for the actual filter.
The complete toolkit: simulations, solver, cases, and both unique versions of the Sustainable Futures Lab game. Everything you need to prepare with confidence.
Three-hour prep for candidates who want one Redrock case per template, two Sustainable Futures Lab missions, and the Sea Wolf solver.
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