So you know money...
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lets see .... A Cpian puts 10,000 dollar in a Weekly trading scheme. -> About half the time, He makes an 80% gain. -> The other half, he makes a 60% loss. One year later, how much money he will have? a> 1.95 b> 14,000 c> 140,000 d> 1.4 Million e> 131 Million f> I don't want to answer and the question sucks No Marks without explaination ;P Quartz A Good Name Is Better Than A Good Face- old chinese proverb My first article^
my answer: d> 1.4 Million or: 1,420,429.32 to be precise. logic: 5,000 * 1.8 + 5,000 * 0.4 = 11,000 (which is initial * 1.1) so for each week multiply by 1.1, so answer = 1.1^52 * 10,000 now lets see if i'm right...
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Quartz... wrote:
About half the time
He makes about an undeterminable amount, based upon the phrasing of your question. You also need to know if he trades all the stocks weekly, or just some of them. Does he ever take any off-the-top? Does he ever invest more? Questions like this need to be explicitly worded. I win. What's my prize?
I agree... that about theoretically shoots the question in the head. Apart from your questions I'm also wondering if he bought a Lamborghini halfway thru the year and therefore halved his capital? Also maybe he won a few grand at the casino and invested that which further affects the outcome. ;)
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Excellent , if you have waited a bit you would have seen a lot of mixed answers :) My first article^
i'm confused :confused: .. are we supposed to post the answer? All these posts and no answers... cool problem BTW... had me scratching my head for a few minutes :-D
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I agree... that about theoretically shoots the question in the head. Apart from your questions I'm also wondering if he bought a Lamborghini halfway thru the year and therefore halved his capital? Also maybe he won a few grand at the casino and invested that which further affects the outcome. ;)
Or maybe he shafted his bookie, and got his knees broken - hospital expenses will drastically cut into the money his bookie would never give him! (Other question Quartz never answered - what is the cost of being involved in the scheme to begin with? Is it up-front, or a cut of the profits?)
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Drat... now i'm all curious...
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my answer: d> 1.4 Million or: 1,420,429.32 to be precise. logic: 5,000 * 1.8 + 5,000 * 0.4 = 11,000 (which is initial * 1.1) so for each week multiply by 1.1, so answer = 1.1^52 * 10,000 now lets see if i'm right...
Ashley van Gerven wrote:
now lets see if i'm right...
I don't think you're correct. Mainly because you split the 10 grand. You don't gain 80% on 5000 dollars while you lose 60% on 5000 on a single week. Either he gains 80%, or he loses 60%. The problem statement says that he starts out with 10 grand, and every second week time he gains 80%, and all other weeks he loses 60%. My interpretation of the problem is that he get's either 80% or loses 60% of what he's currently got, and all the money stays in the scheme. The problem is very similar to compound interest problems: Bob starts out with X dollars in the bank. He gets Y% interest of what he's got on the bank annually. Bob does not withdraw any money. How much money does Bob have after Z years? The only thing that differs is that he's getting 80% back or loses 60%. So, the correct answer should be (IMO), 10000 * 1.8^(52/2) * (1 - 0.6)^(52/2) which is approximately 1.95. -- Pictures[^] from my Japan trip.
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Ashley van Gerven wrote:
now lets see if i'm right...
I don't think you're correct. Mainly because you split the 10 grand. You don't gain 80% on 5000 dollars while you lose 60% on 5000 on a single week. Either he gains 80%, or he loses 60%. The problem statement says that he starts out with 10 grand, and every second week time he gains 80%, and all other weeks he loses 60%. My interpretation of the problem is that he get's either 80% or loses 60% of what he's currently got, and all the money stays in the scheme. The problem is very similar to compound interest problems: Bob starts out with X dollars in the bank. He gets Y% interest of what he's got on the bank annually. Bob does not withdraw any money. How much money does Bob have after Z years? The only thing that differs is that he's getting 80% back or loses 60%. So, the correct answer should be (IMO), 10000 * 1.8^(52/2) * (1 - 0.6)^(52/2) which is approximately 1.95. -- Pictures[^] from my Japan trip.
good point... thanks for explanation
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lets see .... A Cpian puts 10,000 dollar in a Weekly trading scheme. -> About half the time, He makes an 80% gain. -> The other half, he makes a 60% loss. One year later, how much money he will have? a> 1.95 b> 14,000 c> 140,000 d> 1.4 Million e> 131 Million f> I don't want to answer and the question sucks No Marks without explaination ;P Quartz A Good Name Is Better Than A Good Face- old chinese proverb My first article^
Sorry guys , i got unplugged .... Jörgen Sigvardsson Got it right the first time so i asked him to hide the solution for you guys to ponder more. here is the answer
Quartz... wrote:
A Cpian puts 10,000 dollar in a Weekly trading scheme. -> About half the time, He makes an 80% gain. -> The other half, he makes a 60% loss.
W0 = 10000 For the first week Jim final amount is W1 = 1.8 * 10,000 // ( 80 % gain) W1 = 18000 In the second Week Jim starts loss, i.e., W2 = 0.4 * W1 //( since (W2-W1)/W1= -0.6 ) W2 = 0.4 * 18000 = 7200 After Two weeks, Jim's net account value becomes .72 of 10000 = 7200. For 52 weeks (for a year) = 26 couple weeks ( for 80% gain each first week and 60 % loss each second week) Jim will have 10000*0.72^26[^]= ~1.95 I am sure you all will like the solution :) ciao. note : The question was created by the famous mathematician John Allen Paulos [^] in his book A Mathematician plays the stock market[^] --- My first article^
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Drat... now i'm all curious...
---- Scripts i've known... CPhog 0.9.9 - make CP better. Forum Bookmark 0.2.1 - bookmark forum posts on Pensieve Print forum 0.1.1 - printer-friendly forums
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Quartz... wrote:
About half the time
He makes about an undeterminable amount, based upon the phrasing of your question. You also need to know if he trades all the stocks weekly, or just some of them. Does he ever take any off-the-top? Does he ever invest more? Questions like this need to be explicitly worded. I win. What's my prize?
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I agree... that about theoretically shoots the question in the head. Apart from your questions I'm also wondering if he bought a Lamborghini halfway thru the year and therefore halved his capital? Also maybe he won a few grand at the casino and invested that which further affects the outcome. ;)
Sorry for the delay was unplugged... here[^] is the solution for the weekly strategy problem --- My first article^ --- My first article^
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d? ill delete after you reply
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Ashley van Gerven wrote:
now lets see if i'm right...
I don't think you're correct. Mainly because you split the 10 grand. You don't gain 80% on 5000 dollars while you lose 60% on 5000 on a single week. Either he gains 80%, or he loses 60%. The problem statement says that he starts out with 10 grand, and every second week time he gains 80%, and all other weeks he loses 60%. My interpretation of the problem is that he get's either 80% or loses 60% of what he's currently got, and all the money stays in the scheme. The problem is very similar to compound interest problems: Bob starts out with X dollars in the bank. He gets Y% interest of what he's got on the bank annually. Bob does not withdraw any money. How much money does Bob have after Z years? The only thing that differs is that he's getting 80% back or loses 60%. So, the correct answer should be (IMO), 10000 * 1.8^(52/2) * (1 - 0.6)^(52/2) which is approximately 1.95. -- Pictures[^] from my Japan trip.
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Though you got it correct on the first time but here[^] is the detail solution if you want. Also there is an assumption that One year = 52 weeks which is not always correct :) cheers --- My first article^
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Ok, so it's an old thread, but I'll bite. This is high school maths. Suprised noone else answered
Jörgen Sigvardsson wrote:
Counter question: If he starts out with 10000 dollars, and puts the money in a fund, which gives an average 10% interest every year, how long before he has earned 100000?
If he has earned 100,000 then his balance will be 110,000 (it includes his starting balance. So an expression for the solution would be:- 110000 = 10000 * 1.1 ^ n where n is the number of years we're looking for, and 1.1 is 110% (the compound interest figure). so, simplified a bit, 11 = 1.1 ^ n Therefore, ln(base 1.1) 11 = n ~ ( ln 11 / ln 1.1) = n n = 25.16 so after 26 years he'll have his money. Do I get a prize?
using System.Beer;