Odds of something happening after x amount of spin/tries

Lets say something has a 10% chance of happening. Then lets say you do that thing 10 times. What is the % that the thing happens. I know very broad.

For gambing scenario.

Lets say the chances of hitting a on a 3 reel slot machine 3 single bars is 1/10. After 10 spins what is the % that you hit 3 single bars. What is the formula to figure this out?

Thanks In Advance :D

Quote: MDCasino

Lets say something has a 10% chance of happening. Then lets say you do that thing 10 times. What is the % that the thing happens. I know very broad.

For gambing scenario.

Lets say the chances of hitting a on a 3 reel slot machine 3 single bars is 1/10. After 10 spins what is the % that you hit 3 single bars. What is the formula to figure this out?

Thanks In Advance :D

I would just do it from the inverse, first. The probability of NOT hitting three single bars is 9/10, and you want ten trials, so a simple formula is:

9/10 * 9/10 * 9/10 ---

.9 * .9 * .9 * .9 * .9 * .9 * .9 * .9 * .9 * .9 = .3487 or 34.87% of you not hitting the 1/10 at all, or 65.13% that you do it at least once.

If the probability of an event occurring is 1 in x, and x trials are performed, then as x increases, the probability of 0 occurrences approaches 1/e = 0.367879, and the probability of 1 or more occurrences approaches 1 - (1/e) = 0.632121.

Quote: MDCasino

What is the formula to figure this out?

Thanks In Advance :D

The formula you seek is

1 - (1 - P)^N

P= probability of success
N = number of trials
^ = to the power of

10% = P
10 = N

= 1 - (1 - 0.1)^10

0.65132156

Hey, it works

thnkx for the help everyone!