How many actions are required for all events to happen?

Question

Analytics

Good afternoon!
Please help with statistics:
There are events with different probabilities, for example
Event 1 - 15%
Event 2 - 10%
Event 3 - 8%
Event 4 - 3%
An event occurs with a certain action.
Can you please tell me how to calculate the number of actions that will be required to complete all the events?
Or eat on material that you can read in order to understand for yourself, you got lost in theory.
Thanks in advance!
UPDATE: The probabilities are independent, that is, only one action is always performed, it is impossible to complete all events at once with one action.
As an analogy - collecting items in an RPG, each item has its own probability, but it is impossible to knock out all the items from one mob at once. You need to find out how many mobs it will take to kill to get all the items.

Answer 1

3/100 - once the rarest 3% event.
The rest - more often.
Multiply, we get 0.0036% of the fact that all events will occur.
100/0.0036=27777.777(7)
Rounded up to the nearest whole number: 27778 actions are required for all events to happen.
If overlapping (interchangeable) events: 6945 actions required.