Mathematics: Post your doubts here!

[freezingfires]

(i)
So P(X=0) means when no blue is taken,
it will be
7/1o x 6/9 x 5/8 x 4/7 = 1/6
first 7 orange from 10 total, then 6 from 9 total (because one is taken) etc..

P(X=1)
(7x6x5x3) / (10x9x8x7) x 4 = 1/2
we will take 3 from orange so first 7 then 6 then 5 left, for blue we take once so only 3
down is total number, that is, 10 then 9 , 8 ,7
x4 because blue can be taken first second third or fourth

(ii)
for 0 we know 1/6
for 1 we know 1/2
for 2 it will be 4C2 x (3x2x7x6) / (10x9x8x7) = 3/10 [i take 4 combine 2 to get how many ways can we get 2 blues]
for 3 it will be 4C3 x (3x2x1x7) / (10x9x8x7) = 1/30

X=x..... || 0 || 1 || 2 |||| 3 |
P(X=x) |1/6|1/2|3/10| 1/30|

Thanks a lot PhyZac !!That was really helpful....May you pass with excellent grades .Ameen.I also posted a question in Physics thread any help will be highly appreciated

 

[AlishaK]

Can someone please explain how question 8(full) is solved? Which steps must be included etc.

This paper

Did you get it? or u still need some help?! let me know, I'll explain you then

 

[PhyZac]

I've watched the video. It still doesn't make sense. If you take the class boundaries as 0 and 9.5, you'll get the midpoint as 4.75, whereas the mark scheme clearly states it as 4.5. That's what I don't understand!!!!!!!!!!!!!!!!!!!!!!!!!

I found this.http://ncalculators.com/math-worksheets/how-to-calculate-class-interval-arithmetic-mean.htm
errrrrrr........

Well, May Allah S.W.T help you with this thing! Aameen.
I think it is a matter of acceptance.

 

[daredevil]

daredevil
They told us that 225 out of the 900 cartons has more than 1002 milliliters. So what is the probability that a carton has more than 1002 milliliters? It's 225/900= 0.25. So if we were to standardize 1002 milliliters, you'd get a z value that would correspond to a probability of 0,25 in the normal distribution table. But you don't have 0.25 in the table, so you (1-0.25 = 0.75). So the probability that you would be looking for in the table is 0.75. Which is 0.674. Since the probability is GREATER than 1002, the sign won't change in this case.

oooh thanks... i was thinking about subtracting some but lost my bearings so couldn't wrap my head around wat to subtract even though it was pretty clear... thanks a bunch

 

[daredevil]

ok look here:
P(A) = 1/3
P(B) = 5/9

are these events mutually exclusive??
plz give an explnation too like working and all cz i'm not sure if i'm doing it ryt...

also explain if they are independant events...
and are they exhaustive events...
again with the working and stuff. thanks a lot

 

[syed1995]

ok look here:
P(A) = 1/3
P(B) = 5/9

are these events mutually exclusive??
plz give an explnation too like working and all cz i'm not sure if i'm doing it ryt...

also explain if they are independant events...
and are they exhaustive events...
again with the working and stuff. thanks a lot

LOL.. one can't solve it without the data... It can be both... link the question.

 

[Anika Raisa]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_qp_32.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_ms_32.pdf

Q7 iii) why is arg(1+2i) - arg(1-3i) = arg(u) ??

Anika Raisa ?

See
lets take x=1+2i n y=1-3i now there is a general rule saying: arg(x/y)=arg x - arg y

https://www.xtremepapers.com/community/attachments/cnf1-jpg.25812/

So in here u=x/y so arg u= arg x-arg y !

Hope i cud help u .... Esme.

 

[Anika Raisa]

ok look here:
P(A) = 1/3
P(B) = 5/9

are these events mutually exclusive??
plz give an explnation too like working and all cz i'm not sure if i'm doing it ryt...

also explain if they are independant events...
and are they exhaustive events...
again with the working and stuff. thanks a lot

C,
for 2 events A n B...
if P(A intersection B)= P(A)*P(B)
then A n B are independent!
If P(A intersection B )=0
then A n B are mutually exclusive!

this is the general explanation!! But like syed1995 i wud say u nid to link d question --- here u hv nt given enough data to graw conclusion u c!

 

[daredevil]

LOL.. one can't solve it without the data... It can be both... link the question.

i dnt have the link .. its in my past paper topical and the address of the papr is not given. but i'll try to send a picture of it. wait

 

[daredevil]

This is the question syed1995 Anika Raisa

 

[Anika Raisa]

oh w8! i have it done i m writinng in a min!ok!

This is the question syed1995 Anika Raisa

 

[Anika Raisa]

This is the question syed1995 Anika Raisa

C over here u got p(A)=1/3 in i
n P(B)=5/9 in ii

now A intersection B means that the score differ by 3 or more and also there product is greter than 8

so P(A intersection B)=6/36

not 0 so A n B are not mutually exclusive!!
Btwn dis is frm on06 or mj06...

Btwn post ur S1 doubts here: https://www.xtremepapers.com/commun...oubt-post-your-doubts-here.25911/#post-537193

Hope i cud be helpful!!!

 

[Anika Raisa]

STATISTICS PPL!!! POST UR DOUBTS HERE!!!!
https://www.xtremepapers.com/commun...oubt-post-your-doubts-here.25911/#post-537193

For stat ppl!!BOTH S1 n S2!!

sma786
daredevil

I see a lot of stats related posts here, anyone up for answering P3 doubts ?

 

[Esme]

See
lets take x=1+2i n y=1-3i now there is a general rule saying: arg(x/y)=arg x - arg y

https://www.xtremepapers.com/community/attachments/cnf1-jpg.25812/

So in here u=x/y so arg u= arg x-arg y !

Hope i cud help u .... Esme.

Omg yes ! Thank you... I forgot that rule !!

 

[syed1995]

This is the question syed1995 Anika Raisa

I will take a look tomorrow.. currently preparing for the computer paper tomorrow

 

[daredevil]

I will take a look tomorrow.. currently preparing for the computer paper tomorrow

np man... anika already helped out. thanks anyways and Good Luck for tommorow

 

[Anika Raisa]

no problem it happens!!!

Between Esme cud u also help me wid question no. 10 of on11 variant 33!
HERE is the link:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w11_qp_33.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w11_ms_33.pdf

Omg yes ! Thank you... I forgot that rule !!

 

[Esme]

no problem it happens!!!

Between Esme cud u also help me wid question no. 10 of on11 variant 33!
HERE is the link:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w11_qp_33.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w11_ms_33.pdf

Okay I'll give it a try, if I'm able to do it ..will definitely let you know

 

[Esme]

ln(x²) is not the same as [ln(x)]². Try again using the latter!

You're right .. thanks Dug! That's the mistake I was making !

 

[applepie1996]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_qp_32.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s12_ms_32.pdf

Q9 ii) I can't seem to get the answer, even though I think I'm integrating it right.
We have to integrate x lnx^2
I'm doing it by integration by parts but I don't get the answer as in the marking scheme..
Anyone? Please show me the workings

applepie1996

sorry i couldn't so your question
i got a little busy
but if you still don't get it
i can explain it to you