Poker - Maths Genius Needed $50

CoD

Hey, loooong time lurker, used to post a bit here, but still been reading.

Basically I have a job interview very soon, and you have to pass a maths exam to get in. But I havnt looked at this stuff since I left school.

Its short, and not that hard if you studied maths, bit of calculus, standard deviation, logic stuff.

I can do most of the questions but, I dont know if my answers are correct, or if I am using the easiest method, theres a 20min time limit on the paper! So speed is important.

Be very glad if anyone could answer the questions on it, maybe on paper with written explanation of what you are doing etc. Please send by Saturday if possible, earlier you are more chance of getting the $50.

Best one gets $50 sent over Full Tilt or Stars. Maybe smaller amounts for people that help out too.

You can PM me for my email address to send me your answers.
Cheers

PS Mods I know not technically a poker question, but it is maths based and this is the only forum on boards I use. And it will be gone by sunday as I need the answers before then.

RoadSweeper

I cant help, but what job as a matter of interest?

oq4v3ht0u76kf2

You'll have a PM in twenty minutes.

digiman

Anyone who recently done honours leaving cert maths should be able to answer most of these without any trouble. To be honest I have done all these before but it's being quite a while ago so it would require me having to study to get the answers for the calculus ones or the SD ones.

CoD

RoadSweeper wrote: »

I cant help, but what job as a matter of interest?

Its computer programming but for banks, stocks and shares kinda thing.

I have done it all before, but I left school 5-6yrs ago!
So I dont have full confidence in my answers or methods.

Baring in mind its non calc, so i assume you leave Pi in as Pi etc. not 3.14

CourierCollie

Jasus, I'd need 20 minutes for each question. And I'd still fail!

The_Daddy_H

Any one in particular you want the answer to?

CoD

The_Daddy_H wrote: »

Any one in particular you want the answer to?

Not really, I have the first 5 done here, and some others, I kinda would like someone to do as much as they can, because even the ones I have done, there might be a better/faster way to do them, plus it will show I have the right answer etc.

The_Daddy_H

They all look more or less straightforward, with no major shortcuts bar knowing the general formulae for the the sum of geometric and arithmetic progressions.

CoD

The_Daddy_H wrote: »

They all look more or less straightforward, with no major shortcuts bar knowing the general formulae for the the sum of geometric and arithmetic progressions.

Alright, i'll probably get there myself with the continued use of wikipedia, google and friends!
But any one wants to write out the methods and answers and scan them in for a quick $50, would prob do us both a favour

HiCloy

CoD wrote: »

Its computer programming but for banks, stocks and shares kinda thing.

That's a pretty tough maths exam for a programming job. I couldn't be bothered doing them all but if there's any in particular you can't do, post here and I'll try it

CoD

HiCloy wrote: »

That's a pretty tough maths exam for a programming job. I couldn't be bothered doing them all but if there's any in particular you can't do, post here and I'll try it

ok, even theory could be a help, im mainly looking at

8) Is there a quick way to do this? Or is it put there on purpose for people to waste time on and I should leave it out, listing all the multiples of 3 up to 100 and adding would use up way more than 2mins.

9) Im not sure if I can just stick logs in to get the answer

10) what happens when you differentiate a log? I cant remember or a e^2x

11) Cant remember what happens when you take powers out of the e, again is this just sticking in logs?

Mainly problems with logs, I dontknow if I can just stick them in to bring down the powers of e, probably just cant, not sure!

Thanks

HiCloy

CoD wrote: »

ok, even theory could be a help, im mainly looking at

8) Is there a quick way to do this? Or is it put there on purpose for people to waste time on and I should leave it out, listing all the multiples of 3 up to 100 and adding would use up way more than 2mins.

9) Im not sure if I can just stick logs in to get the answer

10) what happens when you differentiate a log? I cant remember or a e^2x

11) Cant remember what happens when you take powers out of the e, again is this just sticking in logs?

Thanks

8) I would waste time on this I'd just take 3*(1+2+...33), for the divisible by 3, then the x3 and 3x numbers, careful not to double count

9) This is an algebra question, e^2x = (e^x)^2. So set it up as

(e^x-2)(e^x+4) = 0
So you get e^x = 2, e = ln2

10) Differential of ln(x) = 1/x. Differential of e^2x = 2e^2x

11) Get e^whatever on one side, everything else on the other and take logs of both sides

CoD

So much help HiCloy! I'll ship you some money once i get fully sorted over weekend.
Just to make sure
"Differential of e^2x = 2e^2x" So when dealing with the e, means you dont subtract one from the power like you would a normal differential?

Alot of its coming back to me but I think I always struggled with logs, have to wiki it up later

Thanks again

newbie2

FFS, thanks God for inventing calculators.

CoD

ok getting somewhere, now thanks to your help!
Just not sure about 10c, I think im right
And think I can do 11 now.

How could you estimate #7 ? Bound to be a wee simple technique?

twerg_85

2 * { (1/2) + (1/4) +(1/8) +(1/16) .....) gets closer and closer to 2.

Hitchhiker's Guide to...

For question 7

obv its a geometric progression.

1) substitute n = 100 for the denominator: we can now take 2/100 out from the summation operator and this leaves us with a simple geometric progression (which will be multiplied by 2/100 to give us our final result)

2) (0.5)^i (where i = 1 ... 100) can be solved using the geometric progression formula = a(1-r^n)/(1-r) where a is the first term in the series 0.5 and r is the rate of increase of the series 0.5. r^100 is so small as to approximate to 0, therefore our formula reduces to a/(1-r) = 0.5/0.5 = 1.

3) this means that the answer is 1 multiplied by 2/100, which is equal to 1/50 or 0.02

in other words, the next time you want to say "well, that's just my 2 cents" - you could instead use the equation given in question 7


EDIT to add: geometric formulas are on wikipedia: http://en.wikipedia.org/wiki/Geometric_progression

spectre

for 10c, you must use the product rule for differenciating the xe^{2x} term.

The answer is f'(x) = 10 + (2x + 1)*e^{2x}

Hectorjelly

This brings back fond memories, I loved leaving cert maths

robinblinds

CoD wrote: »

Its computer programming but for banks, stocks and shares kinda thing.

I have done it all before, but I left school 5-6yrs ago!
So I dont have full confidence in my answers or methods.

Christ! If the bank find out that you don't know if you left school 5 or 6 years ago, you're in trouble. :pac: