Probability Question

Drakkith

Staff Emeritus
2018 Award
An event has an 8% chance to occur per try. How would I calculate the chance of the event occurring at least once after 3 tries?

jbriggs444

Homework Helper
Is the probability in one trial independent of the actual results in the others?

If so, can you write a formula for the event to not occur at all in three tries?

PeroK

Homework Helper
Gold Member
2018 Award
An event has an 8% chance to occur per try. How would I calculate the chance of the event occurring at least once after 3 tries?
The chance of it not occurring in 3 tries is $$0.92^3$$
So, you want $$1- 0.92^3$$

jtbell

Mentor
To gain some insight into this problem, try the following brute-force method. List all the possible outcomes for the set of three tries:

1=no, 2=no, 3=no : probability = 0.92 * 0.92 * 0.92 = …
1=yes, 2=no, 3=no : probability = 0.08 * 0.92 * 0.92 = …
etc.

Enumerate all the outcomes (how many of them are there?), calculate the probability for each one, and add up the ones that meet your criterion.

Drakkith

Staff Emeritus
2018 Award
Awesome. Thanks guys.

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