Author Topic: IGCSE MATHS Doubts  (Read 129841 times)

Offline Ghost Of Highbury

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Re: IGCSE MATHS Doubts
« Reply #840 on: May 17, 2010, 03:22:29 pm »
I understand that Vol. = 1/3 * pi * (2x)^2 * y

But i dont know how it becomes: (4x^2ypi)/3

Can u please explain furthur if possible? Thanks a lot!!


(2x)^2 = 4x^2.
(4x^2 * pi * y )/3 = (4x^2ypi)/3
« Last Edit: May 17, 2010, 03:31:45 pm by A@di »
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Offline Mr.DitD

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Re: IGCSE MATHS Doubts
« Reply #841 on: May 17, 2010, 04:21:35 pm »

(2x)^2 = 4x^2.
(4x^2 * pi * y )/3 = (4x^2ypi)/3

THANKS A LOT!!!! :D

Offline princess12

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Re: IGCSE MATHS Doubts
« Reply #842 on: May 17, 2010, 04:28:57 pm »
can any 1 explain me oct 2009 paper 4  question 1
urgently fast plaese
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Offline Dibss

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Re: IGCSE MATHS Doubts
« Reply #843 on: May 17, 2010, 04:34:14 pm »
can any 1 explain me oct 2009 paper 4  question 1
urgently fast plaese
any particular subpart or the whole question?

Offline princess12

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Re: IGCSE MATHS Doubts
« Reply #844 on: May 17, 2010, 04:35:10 pm »
whole question please with briefly description
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Offline Dibss

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Re: IGCSE MATHS Doubts
« Reply #845 on: May 17, 2010, 04:42:17 pm »
typing it up, gimme some time

Offline princess12

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Re: IGCSE MATHS Doubts
« Reply #846 on: May 17, 2010, 04:42:40 pm »
ok
We should be kind to after teachers

Offline Ghost Of Highbury

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Re: IGCSE MATHS Doubts
« Reply #847 on: May 17, 2010, 04:51:49 pm »
\
can any 1 explain me oct 2009 paper 4  question 1
urgently fast plaese

1a )i) 2/7 * x = 2.4

     2x/7 = 2.4

     2x = 16.8

      x = 8.4
1aii) 8.4/20 * 100 = 42%

1b) 8/12 * 9 = 6kg

1c) Mass of fruits = 3/12 * 9 = 2.25

      Price = 3/7 * 8.4 = 3.6

2.25 Kg = $3.6
1kg = 3.6/2.25 = 1.6

1d) Let the cost of the previous week be x

  (25% of x) + x = 2.4

  25x/100 + x = 2.4

  125x/100 = 2.4

   125x = 240

    x = 240/125 = 1.92

« Last Edit: May 17, 2010, 04:53:21 pm by A@di »
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Offline princess12

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Re: IGCSE MATHS Doubts
« Reply #848 on: May 17, 2010, 04:59:20 pm »
by the way thanx
                       good luck for all subjects
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Offline Dibss

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Re: IGCSE MATHS Doubts
« Reply #849 on: May 17, 2010, 05:11:36 pm »
whole question please with briefly description
whole question please with briefly description
O/N 09 P4
1.
a)meat : vegetables : fruit = 2 : 2 : 3.
total parts =2+2+3=7
2 parts (meat) cost $2.4
X=total cost
2/7X=2.4
x=7/2 x 2.4= $8.4

aii) 8.4/20x100%= 42%

b)meat : vegetables : fruit = 1 : 8 : 3.
8+1+3= 12parts = total mass is 9 kg.
mass of the vegetables = 8/12x9 = 6kg

c) cost of fruits = 3/7x8.4 = $3.6
mass of fruits = 3/12x9 = 2.25kg
cost per kg = 3.6/2.25 = $1.6

d)$2.40, is an increase of 25% on the cost the previous week
cost of the meat the previous week = X
125/100 of X = 2.4
X = 2.4 x 100/125 = $1.92

hope that helps :]

EDIT : omg i am so sorry for the late reply! I clicked ‘post’ and then my net started acting up refusing to work :/ I’d been hoping that the post had appeared before my net went haywire but apparently that didn’t happen :|

Offline big mac

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Re: IGCSE MATHS Doubts
« Reply #850 on: May 18, 2010, 12:18:53 am »
Q4 + Q5 (b) + Q8 November 2002:
http://www.freeexampapers.us/IGCSE/Maths/CIE/2002%20Nov/0580_w02_qp_3.pdf

Q3 June 2003:
http://www.freeexampapers.us/IGCSE/Maths/CIE/2003%20Jun/0580_s03_qp_3.pdf

Q3 (b) (d) + Q5 + Q6 (b) Novermber 2003:
http://www.freeexampapers.us/IGCSE/Maths/CIE/2003%20Nov/0580_w03_qp_3.pdf


Q1 + Q2 (a) (b) (d)+ Q5 (b) Novermber 2004:
http://www.freeexampapers.us/IGCSE/Maths/CIE/2004%20Nov/0580_w04_qp_3.pdf


Q8 + Q9 (b) June 2004:
http://www.freeexampapers.us/IGCSE/Maths/CIE/2004%20Jun/Mathematics%20Paper%203.pdf

Q1 (ii) (d) (c) June 2005:
http://www.freeexampapers.us/IGCSE/Maths/CIE/2005%20Jun/Mathematics%20Paper%203.pdf


Sorry, I know this looks a lot, but most of these questions are direct questions like fast to do, but there are just some which include graphs, transformation, which I am clueless about, so I had to put in the whole question, you don't have to do all the questions even one will be great! P.S this is core theory!


Offline LM

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Re: IGCSE MATHS Doubts
« Reply #851 on: May 18, 2010, 06:36:15 am »
I have so many questions to ask all of you..
and all of them comes from Nov 07/paper 4
http://www.freeexampapers.us/IGCSE/Maths/CIE/2007%20Nov/0580_w07_qp_4.pdf
here are the question :

Q2 (a)(vi)
Q3 (b) (c) (f)
Q4 (b) (c)
Q5 (b) (c)(v)
Q6 (b)(ii)(iii)
Q7 (d)(ii) (e)
Q8 (b)(c)(d)(e)
Q9 (b)(v)(vi)  (d)

Please answer it ASAP!
Tomorrow is the exam!!

Having you in my dreams its like having my worst nightmares.

Offline Mr.DitD

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Re: IGCSE MATHS Doubts
« Reply #852 on: May 18, 2010, 08:26:24 am »
Hi again,

What is the probable A* mark in this year's Maths IGCSE? I think I will get 64 out of 70 so is there any chance that I get an A*?!??

Thanks!

Offline Ghost Of Highbury

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Re: IGCSE MATHS Doubts
« Reply #853 on: May 18, 2010, 10:07:27 am »
Q4 + Q5 (b) + Q8 November 2002:
http://www.freeexampapers.us/IGCSE/Maths/CIE/2002%20Nov/0580_w02_qp_3.pdf

Q3 June 2003:
http://www.freeexampapers.us/IGCSE/Maths/CIE/2003%20Jun/0580_s03_qp_3.pdf

Q3 (b) (d) + Q5 + Q6 (b) Novermber 2003:
http://www.freeexampapers.us/IGCSE/Maths/CIE/2003%20Nov/0580_w03_qp_3.pdf


Q1 + Q2 (a) (b) (d)+ Q5 (b) Novermber 2004:
http://www.freeexampapers.us/IGCSE/Maths/CIE/2004%20Nov/0580_w04_qp_3.pdf


Q8 + Q9 (b) June 2004:
http://www.freeexampapers.us/IGCSE/Maths/CIE/2004%20Jun/Mathematics%20Paper%203.pdf

Q1 (ii) (d) (c) June 2005:
http://www.freeexampapers.us/IGCSE/Maths/CIE/2005%20Jun/Mathematics%20Paper%203.pdf


Sorry, I know this looks a lot, but most of these questions are direct questions like fast to do, but there are just some which include graphs, transformation, which I am clueless about, so I had to put in the whole question, you don't have to do all the questions even one will be great! P.S this is core theory!


Ans 4) a)i) Reflection in x-axis.

aii) Anti-clockwise rotation 90 degree center O

b) Check the diagram attached.

Ans 5b)i) The  volume of the prism = VOlume of cuboid/2. because the prism is half of the cuboid

           Volume of Cuboid = 72cm^3.

          Thus, volume of prism = 36 cm^3.

5bii)     AF*FG.

AF = sqrt(3^2 + 4^2) = 5cm.
FG = 6cm.
       Thus area = 6*5 = 30cm^2

ans8a) roughly measure the distance AB , shud be around 8cm. Multiply it with 30. Answer : Around 240km

8b) 2nd DIagram (part of the circle of radius 5cm Center points A and B)
  c) 2nd  Diagram  (full circle of radius 5cm from center T)

June 2003.

3ai) 7*25 = 175

3aii)25b
3aiii) 100 cents = 1 dollar
        175 cents = 1.75 dollars.

3aiv) 25b/100 = 0.25b

3b) i) c= T/n
     ii) Cost of one bar of chocolate.

3c) i) 8 books - $36

        1 book = 36/8 = $4.5

3cii) 7 books = 36-6.6 = 29.4

       1 book = 29.4/7 = $4.2

3ciii) A = x/y

3civ) A = (x-1)/(y-7)

Nov 2003

ans 3b) i) Volume of cylinder = pi*r2*h = 100pi * 14 = 1400pi = 4400 (approx)

          ii) 4400 + 6000 = 10,400cm^3.

          iii)  25* 30*x = 10400 ---> x = 10400/(25*30) = 13.9cm.

3d doesnt exist.

ans5) (1,7) --> (7,3)

         (1,7) + (6,-4) = (7,3)

     x = 6

     y = -4
5bi) Clockwise rotation of 180 degree about the point(2.5,6)

5bii) Enlargement : Center : (1,7). S.F = 3

5ci) 3/2 * 2 = 3

cii) 4.5*6 = 27

     3/27 = 1/9

d) (7-1)/(1-10) = 6/-9 = -0.66666...

Ans6b) i) 2x+3x+1 + (y) = 9x+4

             y = 9x+4-5x-1 = 4x+3

bii) 9x+4 = 49

     9x = 45

        x = 5cm

     sides : 10, 16, 23.

             

« Last Edit: May 18, 2010, 11:11:19 am by A@di »
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Offline Ghost Of Highbury

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Re: IGCSE MATHS Doubts
« Reply #854 on: May 18, 2010, 10:12:19 am »
Hi again,

What is the probable A* mark in this year's Maths IGCSE? I think I will get 64 out of 70 so is there any chance that I get an A*?!??

Thanks!

yes, provided u have do the other paper well..
divine intervention!