Mathematics: Post your doubts here!

[GetSomeLife]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s04_qp_2.pdf

Explain Question 15 and 18!!

15:
Area of smaller triangle/area of larger triangle = [length of smaller triangle/length of larger triangle]^2
11/99 = (BC/12)^2
11/99 = BC^2/144
BC^2 = 1/9 * 144 = 16
BC = 16^(1/2)
BC = +- 4

Since length can't be negative
BC = 4 cm

18:
a) Pythagoras theorem:
Let the distance be 'x'
x^2 = 83^2 + 78^3
Simplify:
x = 113.8990781
x = 114
b) Let the bearing be (90 - y)
Tan y = Opposite/adjacent
y = Tan inverse (78/83)
y = 43.2

Bearing = 90 - y = 46.8 = 047 degrees

 

[GlitteringLights]

does any one have any idea what formulae other than n(EuMuP)=n(E)+n(M)+n(P)-n(EnM)-n(MnP)-n(PnE)+n(EnMnP)
for venn diagrams? and is this one even correct? o.o
thanks

 

[GetSomeLife]

does any one have any idea what formulae other than n(EuMuP)=n(E)+n(M)+n(P)-n(EnM)-(MnP)-n(PnE)+n(EnMnP)
for venn diagrams? and is this one even correct? o.o
thanks

Why do you need formulas?

 

[GlitteringLights]

Why do you need formulas?

because apparently we need them for some questions 0.0 dont we?

 

[bluefa1con]

BUT HOW WE WILL WRITE IT IN EXAM BECAUSE ACCORDING TO MY TEACHER YOU CANNOT USE OR WRITE LOG IN EXAM B/C TS NOT INCLUDED IN IGCSE

FOR STARTERS YOU DONT USE ALL CAPS
secondly the questions like that are for only 1 mark so you dont need to show working

 

[bluefa1con]

Aoa wr wb,
http://www.xtremepapers.com/community/attachments/prob3-png.8474/
could someone pls help me with this question!??

i answered that question few pages back

 

[bluefa1con]

because apparently we need them for some questions 0.0 dont we?

you dont need formulas for ven diagrams
just have a look at given info and you can solve the question
any question you have came across that needs that formula?

 

[bluefa1con]

I Need Guide on Preparation of Maths paper 4!!!!!

man up you dont need a guide
solve past papers looks at marks scheme for examiners point and you will be more than good to go

 

[GetSomeLife]

because apparently we need them for some questions 0.0 dont we?

Nopes

 

[bluefa1con]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s04_qp_2.pdf

Explain Question 15 and 18!!

dude i answered your 1st post and explained there
have a look

 

[bluefa1con]

can anyone gimme the questions as they finish i'll start at 1300 ... so pleeeeaase ;'( !!

all the papers will start and end at same time so yeah good luck sitting out side for questions

 

[GlitteringLights]

(yeah this one was from a worksheet my teacher gave)
"Out of 68 pupils in a school, 30 take english, 50 take math, and 24 take physics. if 10 take math and physics, 14 take english and physics and 22 take english and math, how many take all three subjects?
i asked my teacher for help on this so she gave me the formula i posted above.
if you know how to solve this without a formula please tell me
thank you

 

[bluefa1con]

(yeah this one was from a worksheet my teacher gave)
"Out of 68 pupils in a school, 30 take english, 50 take math, and 24 take physics. if 10 take math and physics, 14 take english and physics and 22 take english and math, how many take all three subjects?
i asked my teacher for help on this so she gave me the formula i posted above.
if you know how to solve this without a formula please tell me
thank you

is the answer 10?
if so i ll explain the method

 

[GlitteringLights]

is the answer 10?
if so i ll explain the method

yeah the answer is 10 :O

 

[bluefa1con]

yeah the answer is 10 :O

i have solved such question before
your sir missed a part of question which is something like each student must choose at least 2 subjects
you dont need a formula in such case just a over view of what you is given
ignore the ven diagram
the formula your teacher gave you will only work in this question only because conditions are different every time
the number of intersections given is for students who choose 2 subjects
the total number-intersection will give you the number of students who didnt take 3 subjects
subtract the final from 68 you get 10
bit hard to explain here lol but i think you ll get it

 

[GetSomeLife]

(yeah this one was from a worksheet my teacher gave)
"Out of 68 pupils in a school, 30 take english, 50 take math, and 24 take physics. if 10 take math and physics, 14 take english and physics and 22 take english and math, how many take all three subjects?
i asked my teacher for help on this so she gave me the formula i posted above.
if you know how to solve this without a formula please tell me
thank you

is the answer 10?
if so i ll explain the method

Yep. It's 10

 

[slayer]

Hi! please I need help with Q19 whttp://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_w02_qp_2.pdf

 

[GlitteringLights]

i have solved such question before
your sir missed a part of question which is something like each student must choose at least 2 subjects
you dont need a formula in such case just a over view of what you is given
ignore the ven diagram
the formula your teacher gave you will only work in this question only because conditions are different every time
the number of intersections given is for students who choose 2 subjects
the total number-intersection will give you the number of students who didnt take 3 subjects
subtract the final from 68 you get 10
bit hard to explain here lol but i think you ll get it

k just to clear things up :
you add up the same "criterias/ range of values"
subtract from the larger
and subtract the value you obtain from the original answer?
correct?

 

[bluefa1con]

Hi! please I need help with Q19 whttp://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_w02_qp_2.pdf

 

[bluefa1con]

k just to clear things up :
you add up the same "criterias/ range of values"
subtract from the larger
and subtract the value you obtain from the original answer?
correct?

yeah add all the number of elements for set given
subtracted but the info given to get the actual number without repetition
you subtract this actual value from universal set to get the number of missing values