In a program I am working on I am using the formula z = 1 - ((1 - x) ^ y), where 'z' is the cumulative probability of an event occurring over 'y' attempts with a 'x' percent chance of the event occurring on each individual attempt.

This works fine except I need the formula rearranged so it solves for 'y' attempt using a known 'z' and 'x'.

Appreciate any help, thanks!

## Bookmarks