Trying to figure out a formula...

BerserkBeast - Sanctuary

Hello all Its your favourite kitty b:chuckle D<

But let's get straight to the point b:cute

Im trying to build a tool in Excel, and Im trying to figure out a formula to calculate success rate with multiple tries....not sure how to say this in English, but I'll give it a try with an example.

(1)
Let's say I have a 10% success rate on something, and I give it 4 tries, which formula I need to calculate the chances of success % ? and with 5 tries? 6?.
Off course the formula must adapt to whatever value I put, like 4% chances and 200 tries....I hope you got the idea.
For example, if the success rate is 99% and I give it 2 tries, the chance of success should be 99,9% right?

(2)
The second tool its slightly more complex, this time its not a single event but a multi-stage event.
The refining thing on Perfect World its the perfect example. Let's say I want to buy a tool to determinate how many tries I need to refine something +6 by inputting custom chances of success for each step (Like 50% for 2>3 ; 40% for 3>4 and whatever....).
Off course this time the formula must consider that for each fail it has to start from zero, means if the 5 > 6 fails it have to start from 0 > 1.
So basically this tool has:
- A custom number of steps
- A customizable chance of success for each step
And it gives the average number of tries to succeed to get up to the last step.

Anyone has an idea, at least for the tool #1?

Elenacostel - Heavens Tear

(1) I think that requires the use of the s, t, or z distribution. I forgot all my statistics, and I'm sorry if this is of no help to you.

(2) I don't have the direct answer, but if you are looking for a refining simulator, you can use either Asterelle's Refining Simulator or WarrenWolfy's Spreadsheet. Somehow, though I think you already know of these two tools, so is there something else on top of those that you wanted?