- My Forums
- Tiger Rant
- LSU Recruiting
- SEC Rant
- Saints Talk
- Pelicans Talk
- More Sports Board
- Fantasy Sports
- Golf Board
- Soccer Board
- O-T Lounge
- Tech Board
- Home/Garden Board
- Outdoor Board
- Health/Fitness Board
- Movie/TV Board
- Book Board
- Music Board
- Political Talk
- Money Talk
- Fark Board
- Gaming Board
- Travel Board
- Food/Drink Board
- Ticket Exchange
- TD Help Board
Customize My Forums- View All Forums
- Show Left Links
- Topic Sort Options
- Trending Topics
- Recent Topics
- Active Topics
Started By
Message
re: OT Math problem
Posted on 9/12/17 at 1:07 pm to NYNolaguy1
Posted on 9/12/17 at 1:07 pm to NYNolaguy1
E) None of the above
0
Posted on 9/12/17 at 1:19 pm to slackster
quote:
What are the chances of a 100-year flood happening more than once in a decade?
That was a FE question. I can't remember the distrubution or equation off the top of my head right now.
100 year interval with one flood there's 1% (1/100) chance of it happening each year.
Since there is 1% chance of it happening each year there is also a 99% chance that it does not.
Over 10 years, there is a (0.99)^10 chance of there NOT being a flood, or 0.904 -> 90.4%
Therefore, you have a 9.6% chance of there WILL be a flood.
Posted on 9/12/17 at 1:20 pm to NYNolaguy1
D
Some of the dumbest frickers I've ever met have P.E. at the end of their name....
Some of the dumbest frickers I've ever met have P.E. at the end of their name....
Posted on 9/12/17 at 1:21 pm to 50_Tiger
So, should be .096 x .096 that there will be two?
0.84% chance?
0.84% chance?
Posted on 9/12/17 at 1:26 pm to LSUBoo
edit I fricked up and did only for one
Yes Boo, 0.096 x 0.096 = 0.009216 or 0.9% chance of 2 or more in 10 years.
Yes Boo, 0.096 x 0.096 = 0.009216 or 0.9% chance of 2 or more in 10 years.
This post was edited on 9/12/17 at 1:28 pm
Posted on 9/12/17 at 1:40 pm to NYNolaguy1
B because probability and stuff
P = 1-(1-p)^n
P = 1-(1-p)^n
Posted on 9/12/17 at 1:50 pm to NYNolaguy1
If I understand correctly, you want the probability that a flood happens at least once in the next 100 years.
The complementary occurrence of happening at least once is if the flood NEVER happens, so you do:
1 - (probability of never flooding in 100 years)
= 1 - (99/100)^100 = 0.6339
so 63%
ETA: Dammit Lucas
The complementary occurrence of happening at least once is if the flood NEVER happens, so you do:
1 - (probability of never flooding in 100 years)
= 1 - (99/100)^100 = 0.6339
so 63%
ETA: Dammit Lucas
This post was edited on 9/12/17 at 1:51 pm
Posted on 9/12/17 at 1:50 pm to NYNolaguy1
That's on the PE? Don't you mean FE maybe? Seems way to easy for a PE test question and seems like something I remember from the FE.
Posted on 9/12/17 at 1:52 pm to lnomm34
quote:
Discipline?
Since we're talking about floods, I'm guessing electrical. Probably telecommunications.
Posted on 9/12/17 at 1:53 pm to TigerstuckinMS
quote:
Since we're talking about floods, I'm guessing electrical. Probably telecommunications.
Yes it was on the FE EE Exam.
I remember using the electronic book too look it up haha.
Posted on 9/12/17 at 1:55 pm to 50_Tiger
quote:
Yes it was on the FE EE Exam.
You serious? I was just being a dick.
Posted on 9/12/17 at 1:58 pm to TigerstuckinMS
quote:
You serious? I was just being a dick.
The new version of the FE EE at least covers all EE spectrum.
I needed to know Power, VLSI, Telecom, etc.
As well as ProblemStats, Multivariate Calc, and up to 2nd order Diff Q
Passed that bitch the first time.
Kinda mad I frigged up this math question lol.
Posted on 9/12/17 at 2:01 pm to 50_Tiger
quote:
Yes Boo, 0.096 x 0.096 = 0.009216 or 0.9% chance of 2 or more in 10 years.
The chance of exactly 1 100-year flood in 10 years is 9.14%.
The chance of 2 or more 100-year floods in 10 years is .43%. It's a binomial distribution. You cannot simply square the chances of 1 100-year flood in 10 years to get the chances of 2 100-year floods in 10 years.
Posted on 9/12/17 at 2:06 pm to slackster
quote:
The chance of exactly 1 100-year flood in 10 years is 9.14%.
The chance of 2 or more 100-year floods in 10 years is .43%. It's a binomial distribution. You cannot simply square the chances of 1 100-year flood in 10 years to get the chances of 2 100-year floods in 10 years.
I hate you slack, im reading distributions at work
n = 10
X = 2
45 * p^(x) * q^(n-X)
p(x) is the probability of success = 2% or 0.02 (2/100)
q(x) is the probability of failure = 98% or 0.98 (98/100)
p^(X) = 0.02^2 = 0.0004
q^(n-X) = 0.98^(8) = 0.850
45 * 0.0004 * 0.850 = 0.0153
Edit: im friggin up somewhere.
This post was edited on 9/12/17 at 2:18 pm
Posted on 9/12/17 at 2:15 pm to NYNolaguy1
FEMA
there is a 26% chance that a 100 year flood will occur over the duration of a 30 year mortgage.
which is:
(99/100)^30 = .7397 or 74.0% not to happen so
100-74 = 26% to happen
EDIT:
formula is (for flood not to happen):
(99/100)^100 = .366 or 36.6%
therefore 100-36.6 - 63.4% to happen
EDIT: (for 500 year flood)
(499/500)^30 = 94.1% chance not to happen or 5.8% chance to flood over a 30 year mortgage
so those in flood zone X have a 5.8% chance (if right at the 500 year contour line) all the way to just under 26% chance in right up against the 100 year contour, to flood over the course of 30 year mortgage
there is a 26% chance that a 100 year flood will occur over the duration of a 30 year mortgage.
which is:
(99/100)^30 = .7397 or 74.0% not to happen so
100-74 = 26% to happen
EDIT:
formula is (for flood not to happen):
(99/100)^100 = .366 or 36.6%
therefore 100-36.6 - 63.4% to happen
EDIT: (for 500 year flood)
(499/500)^30 = 94.1% chance not to happen or 5.8% chance to flood over a 30 year mortgage
so those in flood zone X have a 5.8% chance (if right at the 500 year contour line) all the way to just under 26% chance in right up against the 100 year contour, to flood over the course of 30 year mortgage
This post was edited on 9/12/17 at 2:21 pm
Posted on 9/12/17 at 2:25 pm to NYNolaguy1
Yeah it's B. CERM eq. 20.20.
Posted on 9/12/17 at 2:36 pm to slackster
I haven't had to do this sort of math in... 20ish years. Amazing how fast I forget it.
Posted on 9/12/17 at 2:56 pm to Steadyhands
quote:
That's on the PE? Don't you mean FE maybe? Seems way to easy for a PE test question and seems like something I remember from the FE.
It was an example problem for the hydrology section (breadth) for a book I am going through.
FWIW, the breadth portion of the PE is very similar to the afternoon portion of the FE.
Posted on 9/12/17 at 2:57 pm to 50_Tiger
quote:
Edit: im friggin up somewhere.
The probability of success is still 1%, not 2%.
The rest of the math is correct, and you'll get .415% chance of 2 100-year floods in a 10 year stretch. The .43% comes form the possibility that there are 2 or more 100 year floods in a 10-year stretch.
Page 3 of 4
Back to top
Follow TigerDroppings for LSU Football News