I suck at high school math these days lol

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Soulstones

Diabloii.Net Member
I suck at high school math these days lol

I cant figure out how to setup this probability problem. Been several years since 10th grade math. :coffee:

Anyway. If some1 could help me out that would be great.

There are 5 triggers. What are the chances of any one of the triggers going off on a "roll" where you roll all the possibilities at once?
The chances of any one of the triggers going off is:
70%
17.5%
5.25%
8.75%
and 8.75% (again)
 
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AeroJonesy

AeroJonesy

Diabloii.Net Member
Re: I suck at high school math these days lol

The chance of only one going off? Or the chance of at least one going off?

edit: Are these, by chance, hit, crit, miss, dodge, and parry?
 
tarnok

tarnok

Diabloii.Net Member
Re: I suck at high school math these days lol

Oh wow. I was about to do this the very, very, difficult way. Which is what I usually do.

So. The complement of "at least one" is "none." That is to say, one of those two events ("at least one trigger firing" or "no triggers firing") has to happen. Which means what you actually want to calculate is the probability that no triggers fire and then use that to find the probability of "at least one" in one easy step.

Assuming that the probabilities of the triggers firing are independent, finding the probability of no triggers firing is very easy.

Edit: I'm assuming you mean making five different rolls all at once since those add up to more than 100%
 
tarnok

tarnok

Diabloii.Net Member
Re: I suck at high school math these days lol

BobCox2 said:
At least is not exact enough - Refer back to combinations and permutations.
if only 1 at a time can go off the chances are different than if say, any of the lower 4 percentages can overlap (each is inculsive of each lower #) but none of them overlap the 70% chance etc.

http://espse.educ.psu.edu/edpsych/faculty/rhale/statistics/Chapters/Chapter7/Chap7.html#Permutations and Combinations
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I think I get what you're saying, but I don't think it works that way because the chances add up to more than 100%. You're rolling d100 for each event, not 1d100 for all five. At least that's the way I see it.

If they are supposed to trigger off of 1d100 though, we'd need to know more information to finish the problem, specifically, what range of numbers on your random number generator trips each trigger.



 
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Soulstones

Diabloii.Net Member
Re: I suck at high school math these days lol

yea i remember that part from high school. Plus, its pretty logically. You dont just add up the chances.


tarnok said:
If they are supposed to trigger off of 1d100 though, we'd need to know more information to finish the problem, specifically, what range of numbers on your random number generator trips each trigger.
Click to expand...
no idea what ur talking about here



 
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Soulstones

Diabloii.Net Member
Re: I suck at high school math these days lol

maybe ill try this approach:


You have a 100 sided dice that you roll 5 times:
Roll 1: anything below 70 is a "win"
Roll 2: anything below 17.5 is a "win"
Roll 3: anything below 5.25 is a "win"
Roll 4: anything below 8.75 is a "win"
Roll 5: anything below 8.75 is a "win"

What are the chances that you "lose" all 5 rolls.


(yes i realize that the dice dont have fractional sides, but if it really bothers you then make it a 10,000 sided dice and multiple the rest by 100 =p )
 
tarnok

tarnok

Diabloii.Net Member
Re: I suck at high school math these days lol

Soulstones said:
maybe ill try this approach:


You have a 100 sided dice that you roll 5 times:
Roll 1: anything below 70 is a "win"
Roll 2: anything below 17.5 is a "win"
Roll 3: anything below 5.25 is a "win"
Roll 4: anything below 8.75 is a "win"
Roll 5: anything below 8.75 is a "win"

What are the chances that you "lose" all 5 rolls.


(yes i realize that the dice dont have fractional sides, but if it really bothers you then make it a 10,000 sided dice and multiple the rest by 100 =p )
Click to expand...
Then the method I originally described is correct and probably the simplest way to find the answer.



 
S

Soulstones

Diabloii.Net Member
Re: I suck at high school math these days lol

What are the chances that you "lose" all 5 rolls.


SORRY, HORRIBLE PHRASING, let me try again:

What are the chances that you dont win on any of the rolls
 
S

Soulstones

Diabloii.Net Member
Re: I suck at high school math these days lol

so about 19.5%

seems like about the right number. Probability can get confusing if you dont know what your doing haha
 
KillerAim

KillerAim

Diabloii.Net Member
Re: I suck at high school math these days lol

AeroJonesy:
The probability of none of them going off is:
(1-.70)*(1-.175)*(1-.0525)*(1-.0875)*(1-.0875)
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Getting REALLY picky here, but can't we assume that the 100-sided die has numbers from 1 to 100 on each side? Therefore, we can ignore fractions. Also, the first roll includes the number 70, so there are 31 losing numbers instead of 30. Accordingly:
  • 1st roll -- losing numbers are 70 thru 100 = 31
  • 2nd roll -- losing numbers are 18 thru 100 = 83
  • 3rd roll -- losing numbers are 6 thru 100 = 95
  • 4th roll -- losing numbers are 9 thru 100 = 92
  • 5th roll -- losing numbers are 9 thru 100 = 92
Chances of losing on all five rolls = .31 x .83 x .95 x .92 x .92 = .207 = 20.7%
 
AeroJonesy

AeroJonesy

Diabloii.Net Member
Re: I suck at high school math these days lol

KillerAim said:
AeroJonesy:

Getting REALLY picky here, but can't we assume that the 100-sided die has numbers from 1 to 100 on each side?
Click to expand...
Far too picky! I was responding to the original problem as posed. That would allow for fractions. And when it was changing to a die roll, the actual number ranges were changed, as you correctly noted.



 
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