Red Rock Study
Marked.Example run · Red Rock Study
What a Red Rock Study review shows you
A fixed example sitting with illustrative answers, graded by the same engine that grades yours. It is not a buyer's result.
Example review
A CaseStar practice sitting with illustrative answers, graded by the same engine that grades yours.
24 of 25 right
CaseStar practice score, not a McKinsey score
Original illustrative answers.
Your one fix
Cost you 8 of 100 CaseStar points
It asked for percentage points. You gave a percent change.
Analysis 3: percentage points vs percent.
- What it askedpercentage points
- −3.43points
- 56.64 − 60.07. Desert Springs’ share minus Otter Lake’s.
- What you didpercent change
−5.71%- −3.43 ÷ 60.07. Dividing answers a different question: “by what percent is it smaller?”
Next timeRead the unit in the question first. “Percentage points” means subtract. “By what percent” means divide the change by the starting value.
Desert Springs is 56.64% and Otter Lake is 60.07%. The gap is −3.43 percentage points; as a share of Otter Lake it is −5.71%. The question asked for the points; the relative change was typed.
Try the method on unseen numbers Two fresh questions. Can you carry the fix across?
Can you use it on new numbers?
The method stays. The figures change. Work this out before checking.
What fixing this answer changes
On this illustrative paper, correcting this answer changes the rounded practice score from 92 to 100/100. The fix’s point cost uses the unrounded answer weight; the overall score is rounded to a whole number. The paper and all other answers stay the same.
Make the correction yourself.
One answer on this paper, checked by the sitting’s grading engine. Then test the method on new numbers.
Weighted answers: 17.35 of 18.85 marks. Raw right-answer count: 24 of 25. Carry-forward credit: 0 answers. A carried error earns its method credit without counting as a right answer. This example paper scores 25 items. Item counts vary by paper.
your score, your main error pattern, where the time went, and the full review for 72 hours Your score, main fix and minutes are included in the free review.
Where the minutes went · Illustrative actual
- Investigation
- Plan 5 minActual 6 min
- Analysis
- Plan 9 minActual 12 min
- Report
- Plan 9 minActual 6 min
- Cases
- Plan 12 minActual 11 min
Practice bank · checked 28 October 2026: 12 study structures in 8 settings. A new sitting generates fresh figures. Example run regenerated and checked 31 October 2026.
Independent CaseStar practice informed by candidate reports. Not McKinsey's software. Your invitation sets the real assessment; timings here are ours.
What comes next
Your practice score does not decide whether you advance. Even a high real-test decile does not promise an interview; follow your recruiter’s next steps.
- Practise a case interview out loud · CaseStar voice practice
- Rehearse a personal-experience interview (PEI) story · CaseStar voice practice
Preparing for another firm?
Practise a BCG case interview. Follow the assessment named in your invitation; BCG assessment practice is currently unavailable here.
Explore Bain Sova and TestGorilla practice. Bain’s invitation names the platform; the configuration depends on your role and office.
Bain digital-assessment guidance · source recorded 9 September 2026. Invitation instructions take priority.