Easy · Probability & Combinatorics · Numerical · ~3 min · #85
A Seven Somewhere Up to a Million
Real interview · Optiver
You pick an integer uniformly from 1 to 1,000,000. What is the probability that it contains the digit 7 at least once?
Hints · 0 of 2 shown
Worked solution
Give the problem an honest attempt first, then reveal the full explanation.
Reported in interviews
Candidate-reported and unverified; the firm may phrase it differently or no longer ask it. The wording here is our own paraphrase, and the solution was written and checked independently of any answers posted at the source.
Related questions
Concepts
Complementary counting
Relevant for
Quant TraderQuant ResearcherQuant Developer