In the group of 23 people the possibility that 2 people have birthday in the same day is about 50%.
First lets count the possibility for the variable group of people.(N-is the number of people in the group)
Let's take one person and remember his birthday. Then let's take second person. The possibility that his birthday won't match with the first person's birthday is (1-(1/365))=364/365.Then let's take third person. the possibility that his birthday won't match the previous two is ((1-(2/365)=363/365. Then the forth....is ((1-(3/365)....The Nth will have ((1-((n-1)/365))=(366-n)/365. So if we multiply all these possibilities we will get that the possibility that all N members of the group have different birthday is
t=(364*363*362*361....(366-n))/(365^n)
[365^n is the equivalent of writing 365 to the power of N)
So the possibility that at least 2 people have birthday on the same day is 1-t
If you count it for t=23 you will see that 1-t is slightly above 50%.
Current ratio
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The current ratio is a financial ratio that shows the proportion of current
assets to current liabilities. The current ratio is used as an indicator of
a c...
6 years ago
6 comments:
Please send all your mind maps - in their original form i.e. as mmap attachments NOT JPEG etc - to:
chris.sivewright@btinternet.com
It is a great pity you re not using this blog for some of the ideas in Debunking Economics...
Yeah...but IT's SO difficult to read)By the way you are doing the book with our mind maps, right?Can you post a copyright?:)
No I am not doing a book (for sale i.e. publishing) with your mind maps. If I did I'd ask you first!
I will be doing a book with mind maps (I have hundreds plus my students outside of EF do them) for sale if 'the business ' doesn't go ahead (i.e. you turn down this wonderful opportunity).
It all depends on what you (collectively) decide over the next 30 hours. I have wasted too much time trying to convince people.
If I go ahead without you lot then I'd expect to have the mind map book ready by Tuesday (as I will sub-contract).
There are about TWENTY other books - I'd expect to take 3-4 weeks for them.
The whole idea being to a) advertise and then b) have them ready by 1 January.
Advertising is expensive so I will only do that if I go ahead with the people outside. I cannot run the risk of relying on a group of people who always want 'in' but don't seem to want to work together.
The whole idea behind the manuals/books is that they are NOT copyrighted i.e. schools pay £40+ etc BECAUSE they can then copy them.
I showed you three sites that sell photocopiable books (I sent a fourth one round today) plus I have given detailed plans as to how the books would work.
I am busy writing exam papers in the OCR style, right now. If we go ahead then they'll be in the books. If we don't then they'll be in 'my' books. Either way you'll be doing them in class!
When I last looked at the list of books, one copy of each adds up to about £600. Taking off photocopying costs and administration and postage that's about £500 profit. Of course off that has to come the leaflets and mailshots - but if, say, 5 copies of every book sold (and ONLY 5) then at a guess that would be a profit of about £1000.
Plus of course all the 'authorship' (for UCAS) - and, as I hope you agree, even preparing these mind maps and books etc all helps you learn your economics! (and that is the main aim...)
Mr.Chris i really want to join. Even though i'm lazy, i will do it.But others?
You have 18 hours left and then the deal's off and I'll start doing the books, planning the adverts, expanding the website etc etc
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