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#1 Re: Help Me ! » Please help me with this finance problem » 2018-05-12 13:34:11

Grantingriver wrote:

Dear Davidtrinh and Mathegocart, the question simply has something wrong with it. The numbers “30 years” and “94.3 years” are irrational (it is like calculating the length of a person, according to some data, and finding it to be 3 km!!). There is no “bank” that accepts this contract. Actually, in normal circumstances, the bank increases the period of payment if the costumer borrows more money until the period reaches a particular number of years (usually 6-8 years), then they would not increase the period no matter what is the amount that was borrowed. Therefore the problem is unrealistic which is not expected from a textbook. The number “30 years” is probably a typo and the correct number seems to be “3 years”. On the other hand, the formula used by “Mathegocart” is probably not the correct one, since this equation is derived to calculate the saving account balance after a period of time in the case that an amount “P” is deposited in the bank (calculating the monthly payment of a loan in this way is a little bit strange). Finally, even if we assume that the number of years was not “30 years”, there would be a number of possible ways to calculate the period depending on the method applied for calculation. Therefore, without any further information, your question can not be solved “correctly”. This is, in fact, the reason why the brilliant mathematicians in this site did not answer this question.

Hi, the question is ambiguously worded, but at a second reasing I realize I misconstrued the problem. Upon utilizing the mortgage formula, I got a time of 359.65 months.. or 30 years, confirming the book.

The compound interest formula for paying off a mortgage is 61858b7aed1d40db9addd9f464b848632bad87e4

payment = P [ i(1 + i)^n ] / [ (1 + i)^n - 1]

payment  = 710

i = interest divided by 12(monthly)(0.055/12)

n(time in months)

WA confirmation

#2 Re: Help Me ! » Please help me with this finance problem » 2018-05-10 23:35:07

I presume you mean 710 to be the principal, P. Now let's solve for t.

125,000 = 710(1 + 0.055/12)^(12t)
125,000 = 710(1.00458)^(12t)
log(176.056338028) = log((1.00458)^12t )
(divide by the logs)
1131.58 = 12t.
And with a swift but succinct slice, we find..
t = 94.298 yrs or 94.3 yrs.

Somewhat peculiar that both you and the book are wrong, but WolframAlpha and Desmos confirms it.

#3 Maths Is Fun - Suggestions and Comments » AIM has been discontinued » 2018-05-09 23:09:28

Replies: 1

Hi, while perusing the Messaging section of my account, I noticed that the "AIM"  field is still present. However, shouldn't it be eliminated?

#6 Re: Exercises » Basic Rounding and Estimating » 2018-05-01 11:29:00

Perhaps he forgot to clear his calculator?

It is indeed 23.678.


#7 Re: Computer Math » Mathematica Help » 2018-05-01 11:24:14

You should peruse some University tutorials on Mathematica, namely.. … /math.html
and the official documentation from Wolfram themself is also pretty beneficial.
And you should learn the novel style of Functional Programming … mming.html
and always peruse Mathematica's SO for help and tips. Here is a nice repository for Mathematica learning. … mming.html


#8 Re: Ganesh's Puzzles » General Quiz » 2018-04-17 23:03:43

Hmmm, after perusing the questions..

#6741 is.. San Marino?

#6742 is.. Monaco?

#9 Re: Introductions » Short intro » 2018-04-16 23:34:42

Welcome to the forums, amiable fellow.

#12 Re: Help Me ! » [ASK] Integral Question » 2018-03-22 23:41:12

I concur with everyone here, using some Geogebra, we can confirm the solution is 18 u^2.


#13 Re: Exercises » probability » 2018-03-13 23:58:40

MellyBigD wrote:

Can someone please help me with these prac exercises, It's due today and I don't know where to get started.

A well-known business school in Cape Town conducted a survey in 2013 amongst its MBA applicants to determine whether students apply to only one business school.  A sample of 2018 students was chosen and the following results were obtained: (rounded to 3 decimals)

Age    Did you apply to more than one school?    
    Yes    No    Total
23 and under    207    201    408
24-26    299    379    678
27-30    185    268    453
31-35    66    193    259
36 and over    51    169    220
Total    808    1210    2018

1.1) What is the probability that a randomly selected applicant is younger than 27                     [1]


1.2) What is the probability that a randomly selected applicant is 24-26  old given that he/she did not apply to more than one school?                                                                 [3]



              … rt/html/11


Hi, spamming us with a multitude of problems is not beneficial to us. Please, if you have any questions, say it in just one thread.

Please read the statsitics link, contaning probability independence and probability rules.

Learn Unionsand intersetions.

#14 Re: Help Me ! » Statistics Probability » 2018-03-13 23:47:05

Hi, spamming multiple threads with the same problems does not accelerate the rate at which we solve your problems.

#15 Help Me ! » Somewhat confused on a quadratic question. » 2018-03-13 11:38:34

Replies: 5

Hi, amiable friends, and I took a quadratics test today. I was somewhat confused by this question.
If the coefficients of a quadratic equation are real, and if one of the roots is (1-sqrt(3)), the other root must be (1+sqrt(3)).
This shouldn't be true, should it? The other root can be anything, and the coefficents would still be real.

#16 Re: Science HQ » quantum nos. » 2018-03-13 11:19:19

bob bundy wrote:

Well here's something to ponder.  The DNA molecule is a double helix with billions of twists.  I purchased a 50m coil of Ethernet cable and it was supplied tightly wound.  When I unpacked it, it fell apart until it was a huge tangle of 'spaghetti'  and it took me hours to untwist it.

So how does DNA uncoil, replicate, and recoil so easily?


Uncoil? Well, thanks to my novel knowledge in Biology, I can tell you a brief picture on how it all works.

DNA, made of two complementary strands, with Adenine and Thymine, and Cytosine and Guanine both pairing together. An  enzyme, Helicase, utilizes the power from changing ATP hydrolysis(coloquially known as the universal energy "currency" of the cell.) and unwinds the Hydrogen bonds between the nitrogenous bases. Topoisomerase, another enzyme, periodically breaks the peptide backbone of one strand to relieve some of that tension created by helicases. As the DNA opens, two forks open, creating a "bubble."
And some small but crucial proteins, single strand binding proteins, stop them from binding back.
Now this is where all the magic happens. Unfortunately the DNA creating micromachine, DNA Polymerase, needs a bit of a "guide" to start DNA synthesis. This is where RNA primase helps, laying down a short strand complementary to the template, and DNA polymerase extends this.

Not finished.

I'll complete when I have more time.

#17 Re: Computer Math » Ten Cool Experimental Mathematics Problems » 2018-03-12 23:50:41

bob bundy wrote:

Leesajohnson* is probably not a bot.  This person put a advert for tutoring services in their signature, which I removed.  The administrators and moderators have discussed this growing problem but decided not to ban automatically but rather to remove the advert and wait to see what the member does next.

Some  ago a person joined to tell us about some new mathematical research they had done and included a link to their book sale page.  The work was genuine but the advert broke our rules.  The person agreed to make a pdf of their work available to MIF members for free and that seemed to be a good compromise.

Some cases are hard to determine such as the recent bit coin maths puzzle post.  Do I want to seem to encourage bit coin? But the puzzle was one that members might want to try.  So I deleted the link but kept the puzzle.


ps. * Also I noticed 6 English grammar and spelling faults in that post.  What sort of advert is it when the 'tutor' cannot write good English?

Make a habit of studying math and this will make you proficient in this subject. It is good to study from books and get tuition from expert tutors, full stop / new sentence starting with 'This' is the indication of replace 'of' with 'for a' better future.

pps.  On the other hand if this is from a bot, then it's entirely appropriate to post it in 'computational math'.

Yes. I am wary of these suspicious people posting some psuedoadvertisements.
And so many [sic]s, making me [sic]!
pps. Hmmmm. Indeed.

#18 Re: Coder's Corner » C language » 2018-03-12 14:56:30

Leesajohnson wrote:

You want to become proficient in c language then I suggest you 'Select My Tutor' where learners find many c language tutors of different locations. Find the relevant tutor for help.

Why are you posting to a thread that is 2 years old?

#19 Re: Computer Math » Ten Cool Experimental Mathematics Problems » 2018-03-12 09:35:37

Leesajohnson wrote:

Make a habit of study math will make you proficient in this subject. It is good to study books and get tuition from expert tutors, is the indication of better future.

Aren't you a bot?
That's not pertinent to this topic, which is computational mathematics.

#24 Help Me ! » Help me program this Java program. » 2017-09-13 15:19:30

Replies: 1

I'm trying to program a Java program that makes a Robot that has a set configuration: (1,1,North,36 beepers). We have an open 10x10 space where I must make it place 8 beepers at (1,1), 7 beepers at (1,2), 6 beepers at (1,3), 5 beepers at (1,4) and so forth and so on. It ends on (1,9) with NO BEEPERS underneath. A beeper is a black circle. We can put beepers on other beepers. I can only use move(); and putBeeper(); ONCE EACH. I've tried using a loop, but it hasn't worked. Can anyone help?
Commands that robot knows(move, putBeeper, pickBeeper, turnLeft)

#25 Re: Maths Is Fun - Suggestions and Comments » Chess » 2017-07-23 05:32:12

Hmmm... all I have to say is that Garbochess seems like a misnomer.

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