Mathematics paper 6 (Stats)

[jaideep]

Need help in Q2 http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w11_qp_61.pdf
And also if anyone could provide some notes on these type of questions, it would be of great help!

 

[jaideep]

am i the only one who finds permutation and combination ANNOYING and HARD !

Are you kidding me, name a single person who's good at it!

 

[pakiboy]

Are you kidding me, name a single person who's good at it!

bro havnt u seen any genius in ur life
It is a conceptual topic there is nthng difficult in it !

 

[shafayat]

hii peeps! One permu combi problem ! the part(ii) I feel a bit annoying
butt even more annoying is part(iii) the probability !!!

- wud be thankful If any of you guys can help -

 

[jaideep]

bro havnt u seen any genius in ur life
It is a conceptual topic there is nthng difficult in it !

Bro, I don't think that someone could answer all the questions right no matter how good he's at it!

 

[Dudu]

Need help in Q2 http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w11_qp_61.pdf
And also if anyone could provide some notes on these type of questions, it would be of great help!

Same problem here. I can get n=40. But clueless on what formula they've used to get SD.

 

[syed1995]

Same problem here. I can get n=40. But clueless on what formula they've used to get SD.

Just remember.. Ex = mean * n and Enumber = number * n

E(x − 25) = 133, E(x − 25)^2 = 3762 and mean = 28.325

Ex = 133+25n
28.325 = (133+25n)/n
28.325n=133+25n
n=40
Ex=133+25(40) = 1133

E(x-25)^2 = 3762
E(x^2-50x+625) = 3762
Ex^2-50Ex+E625= 3762
Ex^2-50(1133)+40(625) = 3762
Ex^2=35412

SD = √(Ex^2/n - (mean)^2)
SD = √(35412/40 - (28.325)^2)
SD = 9.11 Answer

 

[jaideep]

E(x − 25) = 133, E(x − 25)^2 = 3762 and mean = 28.325

Ex = 133+25n
28.325 = (133+25n)/n
28.325n=133+25n
n=40
Ex=133+25(40) = 1133

E(x-25)^2 = 3762
E(x^2-50x+625) = 3762
Ex^2-50Ex+E625= 3762
Ex^2-50(1133)+40(625) = 3762
Ex^2=35412

SD = √(Ex^2/n - (mean)^2)
SD = √(35412/40 - (28.325)^2)
SD = 9.11 Answer

Bro, do you have any good notes for this very topic?

 

[syed1995]

Bro, do you have any good notes for this very topic?

No.. You just need to remember one thing ... Ex = mean *n while Enumber = number * n

and then open all the brackets...

 

[pakiboy]

Bro, I don't think that someone could answer all the questions right no matter how good he's at it!

I thnk he can do!
As i said earlier, one with gud cncepts can actually solve any question!
Take the example of ur teacher cnt she solve every quest?
Atleast my teacher can do it!
So its nt like u cnt get it right every time, the more u prctice the more u get gud at it!

 

[A star]

am i the only one who finds permutation and combination ANNOYING and HARD !

i find it hard not annoying

 

[syed1995]

i find it hard not annoying

I find it interesting.. but it is indeed hard.

 

[A star]

I thnk he can do!
As i said earlier, one with gud cncepts can actually solve any question!
Take the example of ur teacher cnt she solve every quest?
Atleast my teacher can do it!
So its nt like u cnt get it right every time, the more u prctice the more u get gud at it!

well i think stats u can get full but its much harder then in mechanics :/

 

[A star]

I find it interesting.. but it is indeed hard.

not interesting , i find only one chapter interesting and that normal approx i men its so complex that even when you know what to do you still tend to make errors :/

 

[jaideep]

I thnk he can do!
As i said earlier, one with gud cncepts can actually solve any question!
Take the example of ur teacher cnt she solve every quest?
Atleast my teacher can do it!
So its nt like u cnt get it right every time, the more u prctice the more u get gud at it!

Chill out bro, the thing is that your teacher is not gonna write the paper for you, is he/she?
And Obviously you get good with practise!

 

[pakiboy]

Chill out bro, the thing is that your teacher is not gonna write the paper for you, is he/she?
And Obviously you get good with practise!

but the teacher should be an inspiration for u, i bet once u become cnfident u can solve any damn quest.!

 

[pakiboy]

well i think stats u can get full but its much harder then in mechanics :/

u r right bro mechanics is very easy as compared to stats!
i knw bcz i am giving both