Mathematics: Post your doubts here!

[sea_princess]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s03_qp_6.pdf

and

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s11_qp_63.pdf

in S03 question 7i), the midpoint was found using (0+5)/2 but in S11 q3 iii) the midpoint was found using (0+9)/2

how come?

I believe that in june 2011 they took the range from 1 to 10 not from 0 -9

 

[mukki]

please in june 11 63 S1 question 5)iii), i need to know why they used CONTINUITY CORRECTION in the mark scheme although there was no term in the question indicating this like normal approximation or suitable approximation??
please answer soon to help me and others

ok dude listen this might calm you whenever N(number of trials) is very large like above 20 or so always do np and nq to check whether it converges to normal. mostly 5 marks qs like this are to be converted to normal. but always do check. if np >5 or nq >5 then uve got a normal

 

[shan5674]

dude i did it my way first taking P(X>9.2) then adding the probability found to P(X<7.2) ul get the same answer

Thanks got it
BTW could you explain http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_w09_qp_62.pdf Q1 - (ii)? i couldnt find it in the previous pages and i really dont have time to keep scrolling through them all so please?

 

[mukki]

I believe that in june 2011 they took the range from 1 to 10 not from 0 -9

in the summer 2003 one the class boundaries are defined and are continuous like from 0-5 then 5-10 but in june 2011 they arent defined and arent continuous either. so in the 2011 one you have to subtract .5 from the upper class boundaries and add .5 to the lower class boundary

 

[mukki]

Thanks got it
BTW could you explain http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w09_qp_62.pdf Q1 - (ii)? i couldnt find it in the previous pages and i really dont have time to keep scrolling through them all so please?

no problem bro just pray for me anyways you know that q3 is 75 percent of the data right? is the area less then q3 will be.75. P(X<63)=.75 solve and enjoy

 

[nem0]

http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_s11_qp_62.pdf
question no. 6.i
help?

 

[JulyMei]

ohh ok
do you mind helping me with this Q2, i, I made a correct tree diagram but i keep getting 31/30 as the probability.

​

http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_w11_ms_63.pdf​

​

http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_w11_ms_63.pdf​

you have to find P(F) and P(W) and minus out the intersect part..
Hope this help..

 

[mukki]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s11_qp_62.pdf
question no. 6.i
help?

P(X>20)=.10 standardize and solve but dont forget to underroot variance since you have to deal with s.d

 

[JulyMei]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s11_qp_62.pdf
question no. 6.i
help?

if dont understand, just let me know.

 

[sheekha]

http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_s11_qp_62.pdf
Problem no 4 (iii).
sm1 to help plz.. thnks!

 

[shan5674]

no problem bro just pray for me anyways you know that q3 is 75 percent of the data right? is the area less then q3 will be.75. P(X<63)=.75 solve and enjoy

Thankss aloot and yes i sure will
btw im a girl

 

[JulyMei]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s11_qp_62.pdf
Problem no 4 (iii).
sm1 to help plz.. thnks!

_ _ _ S = 5C3
_ _ S S = 5C2

5C3 + 5C2 = 20

Hope it helps.

 

[sea_princess]

in the summer 2003 one the class boundaries are defined and are continuous like from 0-5 then 5-10 but in june 2011 they arent defined and arent continuous either. so in the 2011 one you have to subtract .5 from the upper class boundaries and add .5 to the lower class boundary

but that doesn't five the 4.5 or other values in the markscheme
http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_s11_ms_63.pdf

 

[nem0]

if dont understand, just let me know.

thank you so much.

 

[JulyMei]

thank you so much.

you're welcome.

 

[mukki]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s11_qp_62.pdf
Problem no 4 (iii).
sm1 to help plz.. thnks!

in such qs always write down the number of times an alphabet is being repeated...p=2 s=2 h=1 i=1 n=1 e=1 a=1
select 4 letters which contain NO P and either 1s or 2s. First vl solve for 1s
-since you know that you have to take that s for sure u wont select it hence its 5c3 this means u have selected 3 letters from h i n e a.
-same goes for 2s but this time u have to select 2 letters from h i n e a= so its 5C2 hence sum them up to get 20.

 

[sheekha]

_ _ _ S = 5C3
_ _ S S = 5C2

5C3 + 5C2 = 20

Hope it helps.

Ty

 

[user]

Aoa wr wb!

need help with Q:3 ii of 9709_w10_qp_61.pdf

Khan_971 why did we do that way..the question i asked u earlier...?

 

[JulyMei]

Ty

no problem.

 

[Esme]

plz jus explain the ans for the (iv) part. i understood the rest.
here's the mark scheme: