06-06-2015, 09:22 AM
22
Re: Maths problem.
Originally Posted by Grumblewagon
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Wrong Moyra. Read the question. Using the information given, you were asked to :Show that n² – n – 90 = 0. You were not asked to find how many sweets were in the bag, but from the equation, it is obvious that there were 10 sweets initially.
QED
And yes, I am fun at parties.
I was joking you either know it or you don't, i don't! 
06-06-2015, 09:24 AM
23
Re: Maths problem.
Originally Posted by spitfire
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All I know is that I go for a Number 2, everyday at 7.30am, and do 3 poops, is that a Logarythm?
Nice one Spitty
06-06-2015, 10:20 AM
25
Re: Maths problem.
Originally Posted by Grumblewagon
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This is easy peasy... not like the proper questions we had in 'O' level.....Right, there are 6 orange sweets in a bag containing N sweets, so the probability of choosing an orange sweet is 6/N.
Picking a second sweet there are 5 orange sweets in a bag of N-1.
The combined probability of these events happening are 6/N x 5/(N-1).
We know that this = 1/3 so we get 6/N x 5/(N-1) = 1/3
or 30/ (N² – N) = 1/3 which can be rearranged to n² – n – 90 = 0.
QED
Come on, what do people want these days, to be given the answer on a plate?
06-06-2015, 11:47 AM
26
Re: Maths problem.
Actually, I had difficulty with statistics and probability at 'O' level, but this is more a logical question that can be worked out with a pencil, paper and some arithmetic .I spent ages at uni working over pages of equations and functions to solve problems about power lines and telephony cables. When I started as a computer engineer, I was told to forget all that because it was all about logic. Fortunately, I had spent ages doing that too.
I need a sweetie after all that. Unfortunately somebody has eaten all the orange ones, so it looks probable that I'll get a Lemon one.
OK- here's a fun one for you..... In a football match there are 22 players. What is the chance that two players share the same birthday? (not a trick question - there are no twins or triplets)
06-06-2015, 12:07 PM
28
Re: Maths problem.
OK- here's a fun one for you..... In a football match there are 22 players. What is the chance that two players share the same birthday? (not a trick question - there are no twins or triplets)Well for each player there is a one in 365 chance that today’s it is his (or her!) birthday. There are 22 players. So … is it 365 divided by 22? That would be neat, but I can’t quite convince myself.
07-06-2015, 01:40 PM
30
Re: Maths problem.
This is the Birthday paradox and the answer is initially quite surprizing.Each player could possibly share a birthday with any of the other 21 players. There are therefore 21x22/2 = 231 combinations.
the chances of 2 birthdays being the same is 1-364/365 to the power 231. or 1- .632 = .368 or almost 37%. If you include the referee, it becomes nearer 50%!
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