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Math exercise

Started by scarface, February 28, 2016, 11:22 PM

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scarface

Here is a little problem: If 400 chickens are laying 400 eggs in 4 months, how many eggs are 200 chickens laying in 2 months?
If you are reading this message, you can connect to the forum to solve the problem and vote.
Maybe you will find it tricky. I'll give the solution later.

Vasudev

I'm really bad at math.

scarface

#2
Some users of the forum answered the above question, and I'm going to give the solution.
Few persons answered, I guess this problem may have been somewhat difficult. By the way, someone gave a bad answer. It must be Vasudev.
So, we have twice as less time, and half as much chickens. Therefore, if no predator comes to eat the chickens' eggs (I'm thinking of Vasudev, once again), we should have 2*2=4 times fewer eggs at the end of the period, that's to say 400/4=100 eggs.
Well, I guess we have some maths purists on the forum who want to check this with an equation.

let's assume x is equal to the number of eggs and y the number of eggs laid by one chicken (in one month). We have 400 chickens and 4 months.
Therefore (400*4)*y=x
We know that during the first period of time, we had 400 eggs, so x=400 and 1600y=400
It becomes obvious that y=0.25
Some users may find that this number is very low since each chicken laid only one egg in 4 months. Well, maybe some chickens were ill, others may have been on strike, possibly attending the Occupy-style Nuit Debout movement taking place in Paris’ Place of Republic. Anyway, this maths problem was not meant to be realistic.

Then, during the second period, we have 200 chickens and 2 months, but we don't know x (y does not vary).
200*2*y=x, y=0,25
200*2*0,25=x
x=100
Hence the answer of the question.

scarface

QuoteConsidering 200 chickens in 2 months can lay 100 eggs, 400 chickens in 2 months then should lay 200 eggs, and so 400 chicken in 4 months should lay 400 eggs.
That's indeed the wording of the problem, but you have the answer of the question since you are starting with it: if 400 chickens are laying 400 eggs in four months, how many eggs are 200 chickens laying in 2 months?

QuoteCould you please explain better your ways to calculate this?
You multiplied (400*4)*y=x out of nowhere
Well, I'm going to rephrase it, though it was quite clear the first time. To find the solution, we are going to calculate the average number of eggs that every chicken is laying in one month. (In reality this figure could vary a little, but we make the assumption it doesn't)
We still assume x is equal to the number of eggs and y the number of eggs laid by one chicken (in one month).
We know that we have 400 chickens, 4 months and 400 eggs
Let's assume we have 400 chickens, 1 months and...100 eggs (it's obvious I don't explain it), it's going to be simpler. So we know that x=100
then 400(the number of chicken)*y(the number of eggs laid by each chicken)=100(number of eggs) and it becomes obvious that y=0,25
If we have 4 months, we multiply the right term and the left term by four and we find what I wrote: (400*4)*y=400
Actually, with the wording of the problem, we find that each chicken is laying an average of 0.25 egg each month, or 1 egg in 4 month.
QuoteI mean can the chickens lay an egg more than once? If that's so, then it makes sense.
No matter if one chicken is laying an egg more than once, it's an average. As I said, this figure is not realistic, maybe most chickens are old or ill, maybe they are back from the Jihad and they are missing some body parts, it's possible. If only 5% of the chickens were laying 100% of the eggs, it would mean that these chickens would lay 20 times more eggs than the average, that's to say 5 eggs per months. It's a bit more realistic.

scarface

Well this exercise was not very difficult. For those who like maths you can check the ones that were posted in this topic:
http://www.nomaher.com/forum/index.php?topic=1110.0
You can also try the French bachelor's degree in Mathematics, released a few days ago: http://www.youscribe.com/catalogue/tous/actualite-et-debat-de-societe/actualite-evenements/bac-2016-maths-serie-s-obligatoire-2720710
I did not know Tovagulet, apparently a long-time associate on this forum. It's always interesting to give some exercises, because some users are participating, and it requires sagacity and perspicacity in some cases.
I was thinking that it would be interesting to do accounting exercices. I have a good level in accounting since it's needed in my job. But there are difference between the French standards and the IAS and I would not want to give you wrong answers. For example, the difference between the IAS17 and the recommendations of the French Standards are well-known: While it's obligatory to include a contract of "Finance lease" in the balance sheet for the IAS (meaning that if you are using a leasing contract, you will have a fixed asset on the assets side and a debt on the liabilities side) the lease contract in French standards are usually  shown in the annex, that's to say assigned "off-balance sheet account".