Waiting Time: Average Waits, Yearly Risks, Arrivals and Collecting a Set

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Waiting for something with the same chance each try

Chance each try e.g. 1 in 20, 5% or 1/20

Tries so far

A yearly chance over the years

Chance each year %

Years

Random arrivals

Average per hour (or per period)

Busy if at least

Collecting a set

Items in the set

Boxes bought

Enter your numbers, then press Calculate.

From the book, Chapter 18. Waiting for a six: 6 rolls on average, but still waiting after 10 rolls 16.2% of the time; half the time it comes within 4. A “1-in-100-year” flood (1% a year) over 30 years: 26%; over 100 years 63.4%. Three calls an hour on average: no calls in 5% of hours, six or more in 8.4%. A set of six toys, one per box: 14.7 boxes on average, and only 27.2% within 10 boxes.

Exact arithmetic, worked the way the book shows. Everything stays in your browser: no sign-up, nothing stored or sent.