Mathematics: Post your doubts here!

[Muzammil100]

DOUBT

October/November 2011 PAPER 41 Q:5

PLZZ IF SOMEONE CAN HELP

Which part?

 

[sma786]

Thanks but
"48.51 - 360 = 131.5"

yes so the markscheme says this is the answer .. so ?

 

[Lost_Life]

Hope that helps
View attachment 9304

THANKS A MILLION

 

[Lost_Life]

Hope that helps
View attachment 9304

BUT UM, HOW DO WE FIND THE LENGTH THOUGH?? WE ONLY HAVE 180 AS GIVEN

 

[Lost_Life]

yeah ur ryt, but how do u get it ? i knw its a stupid questn.. buh i thnk it shd b 3.4 .. =\

well um theyre tellin you that you have 2.9 to 1 decimal place
meaning you ad 0.05 to the number
Upper: is 2.95 (2.9+0.05)
Lower: 2.85 (2.9-0.05)
hope that helped

 

[sma786]

well um theyre tellin you that you have 2.9 to 1 decimal place
meaning you ad 0.05 to the number
Upper: is 2.95 (2.9+0.05)
Lower: 2.85 (2.9-0.05)
hope that helped

ohhh oh yeaa i forgot, thanks alot (^_^)

 

[sma786]

http://www.mediafire.com/view/?2z8w71ejmwvf241
Question 7 (d)

 

[Lost_Life]

ohhh oh yeaa i forgot, thanks alot (^_^)

Welcome

 

[sma786]

Guyz .. please help ! i dont understand how to find the nth term of a sequence with different differences ..?
For example ..
1, 2, 4, 8, 16 …… please help !

 

[Abdelrahman Amr]

please i am stuck with a problem plz help
the question is nov/2011/42/Q9/b,i
the show that question

 

[GetSomeLife]

Guyz .. please help ! i dont understand how to find the nth term of a sequence with different differences ..?
For example ..
1, 2, 4, 8, 16 …… please help !

Learn these 2 formulas:

1) This formula can only be applied if the difference is constant between the first and the second, second and third etc.
nth term = a + d (n - 1)
where:
'a' is the FIRST term
'd' is the DIFFERENCE between the terms


2) This formula can only be applied if, in simple terms, the first term is multiplied by a number to get the second term... and the second term is multiplied by the same number to get the third and so on:
nth term = ar^(n-1)
'a' is the FIRST term
'r' is the number they are being multiplied with
1, 2, 4, 8, 16 (for instance)
1*2^(n-1)
= 2^(n-1) Answer


There are many questions you can't solve even when you know these sequences. For that, you need to use some common sense and the sequences already given

 

[Muzammil100]

Guyz .. please help ! i dont understand how to find the nth term of a sequence with different differences ..?
For example ..
1, 2, 4, 8, 16 …… please help !

http://www.s-cool.co.uk/gcse/maths/sequences/revise-it/the-nth-term
This website can help@

 

[always-smile :)]

What are these formulae for .?? plz elaborate .. like cylinder circle or wat ?

the formula of the area of cone

 

[Muzammil100]

http://www.xtremepapers.com/papers/CIE/Cambridge%20IGCSE/Mathematics%20(0580)/0580_w11_qp_42.pdf

Q4)c) i and ii

AND in this one how to rearrage

 

[GetSomeLife]

http://www.mediafire.com/view/?2z8w71ejmwvf241
Question 7 (d)

f(x) = y
f(x) = k
k = y

Find the line with the equation y = 'something' so that that line cuts the graph (s) at three different places

k = 'that something'

please i am stuck with a problem plz help
the question is nov/2011/42/Q9/b,i
the show that question

Q9
b)
i) Probability of first ball being blue = x/25
Probability of second ball being blue = x-1/25-1

x/25 * x-1/24 = 7/100

Simplify:

100x^2 - 100x - 4200 = 0

Divide both sides by 100

x^2 - x - 42 = 0

 

[Abdelrahman Amr]

ok bu how you simplified

 

[GetSomeLife]

http://www.xtremepapers.com/papers/CIE/Cambridge%20IGCSE/Mathematics%20(0580)/0580_w11_qp_42.pdf

Q4)c) i and ii

AND in this one how to rearrage

Q4)
It's a little tricky:


i) No. of biscuits = length of bread/diameter * breadth of bread/diameter
= 30/5 * 20/4
= 24 biscuits

ii) Remaining volume = total volume - 24(volume of one biscuit)
= 1080 - 24( pie*2.5^2*1.8) as the biscuit is a cylinder
= 232 cm^3

 

[GetSomeLife]

ok bu how you simplified

x/25 * x-1/24 = 7/100
x(x-1) / 25*24 = 7/100
x^2 - x / 600 = 7/100
Cross multiplication
100(x^2 - x) = 7(600)
100x^2 - 100x = 4200
100x^2 - 100x - 4200 = 0

 

[Muzammil100]

please i am stuck with a problem plz help
the question is nov/2011/42/Q9/b,i
the show that question

X/25 * (x-1)/24 = 7/100
X²-X/600 = 7/100
X² -X = 42
X²-X-42=0

 

[Muzammil100]

And how to do this?