If I have a 1/80 of getting something, and I try 173 times without success. How do I calculate the chance of that happening?


Also, if we were 4 people trying 173 times to get that 1/80, all with the same chance (1/80) without success. Would that mean the chance each time would be 4/80 ; 1/20



Guest Oct 24, 2017

1+0 Answers


If you have a 1/80 chance of getting a certain outcome, the probability you will get a certain outcome is (1 - outcome)tries.  So, the chance of not getting a 1/80 outcome over 173 tries is (1-(1/80))^173 = 0.1134799259264859, or about 11.35%. With 4 people doing this many tries, the outcome is just as likely as one person doing 4 times 173 tries, so the probability would be ((1-(1/80))^173)^4 = 0.0001658349921536, or about 0.0166%.

helperid1839321  Oct 24, 2017

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