Maths, Addmaths and Statistics: Post your doubts here!

[OakMoon!]

Re: O'level Maths, Addmaths and Statistics help available he

Hahaha! Exatly. To avoid them in Addmaths and A'levels Maths and Further maths, I learnt the use of calculator that allowed me to achieve perfection and eradicate any such wrongdoing.

 

[abcde]

Re: O'level Maths, Addmaths and Statistics help available he

no bhai here we r all for acquiring acha yar plz help me with these questions http://www.xtremepapers.me/CIE/Cambridg ... _qp_21.pdf
Q9 a (ii ), b(i) b and b(ii)

Q9) (a) (ii) cross-sectional area x depth = volume
=> 1/4 * pi * 8 * 8 * d = 800.
=> d = 800/ 16 pi = 15.91549431
Therefore, the depth is 15.9 cm (correct to 3 sig. fig.)

(b)(i)(b) Shaded Area = area of quadrant - area of triangle MON
= (1/4 pi * 8 * 8) - (1/2 * 2x * x)
= 16 pi - x^2. (SHOWN)
(b)(ii) (16 pi - x^2) * 20 = 800
16 pi - 40 = x^2
So x = 3.20 cm (I missed a few steps in this part but I think you can get that).
So I hope this makes it clear. If not, ask away!

 

[abcde]

Re: O'level Maths, Addmaths and Statistics help available he

Nibz, I didn't know you were solving this when I started out! Hmph! This is a little annoying.
@Hamid Ali: Yeah, yeah, you are perfect!

 

[OakMoon!]

Re: O'level Maths, Addmaths and Statistics help available he

HAHAHA! No, I am not. Nobody is perfect and I ain't nobody. Why does yor post looks like a taunt?
Practice makes you better. Silly mistakes can never be eliminated completely, they are part of Mathematics.
@abcde: Nibz stole your wind, didn't he?

 

[xhizors]

Re: O'level Maths, Addmaths and Statistics help available he

xhizors:

For a (ii) => You've got this simple formula for volume => base area x height
Depth of the water actually means the height!
Base area of that prism is a sector here. Area of sector (here) = 1/4 x pi x r^2
Area of sector = 50.27
Now put this in the equation => 800 = 50.27 x height
800 / 50.27 = height => 15.9 cm (correct to 3 sig. fig)

for b(i) b => the shaded area in diag. III = Area of the whole sector - area of that small triangle
Area = (1/4 x pi x 8^2 ) - ( 1/2 . 2x . x )
(16pi) - (x^2) => 16pi - x^2 => SHOWN!

for b ( ii) => Volume = base area (of the shaded region) x height
Volume = 800 cm^3
Base area = 16pi - x^2
Height (length) = 20
Put these values in the formula and you'l get your answer (which = 3.20 cm)
Hope this helped!

arrey yaar that was too easy how i can be that reluctant i think i m exhausted any wayz thanks buddy ..

 

[Nibz]

Re: O'level Maths, Addmaths and Statistics help available he

Okay. I've deleted my post!

 

[xhizors]

Re: O'level Maths, Addmaths and Statistics help available he

no bhai here we r all for acquiring acha yar plz help me with these questions http://www.xtremepapers.me/CIE/Cambridg ... _qp_21.pdf
Q9 a (ii ), b(i) b and b(ii)

Q9) (a) (ii) cross-sectional area x depth = volume
=> 1/4 * pi * 8 * 8 * d = 800.
=> d = 800/ 16 pi = 15.91549431
Therefore, the depth is 15.9 cm (correct to 3 sig. fig.)

(b)(i)(b) Shaded Area = area of quadrant - area of triangle MON
= (1/4 pi * 8 * 8) - (1/2 * 2x * x)
= 16 pi - x^2. (SHOWN)
(b)(ii) (16 pi - x^2) * 20 = 800
16 pi - 40 = x^2
So x = 3.20 cm (I missed a few steps in this part but I think you can get that).
So I hope this makes it clear. If not, ask away!

thanks bhae thanks bhae thanks i get it

 

[OakMoon!]

Re: O'level Maths, Addmaths and Statistics help available he

Okay. I've deleted my post!

You didn't need to do that. Maybe, xhizor understood better reading your post than abcde's. It totally depends on the learner.
If you deleted it because of my post, I was just kidding.

 

[abcde]

Re: O'level Maths, Addmaths and Statistics help available he

HAHAHA! No, I am not. Nobody is perfect and I ain't nobody. Why does yor post looks like a taunt?
Practice makes you better. Silly mistakes can never be eliminated completely, they are part of Mathematics.
@abcde: Nibz stole your wind, didn't he?

Lol. That was just sarcasm. I mean the somewhat pompous way you say "to achieve perfection and eradicate any such wrongdoing" Hahahaha..
Never mind, you've got a point! We're not allowed calculators in Maths paper 1, though.
And Nibz, you didn't have to do that!

 

[abcde]

Re: O'level Maths, Addmaths and Statistics help available he

Againnnnnnnn!! I started out with "Nibz you didn't have to do that" before Hamid Ali. Just letting you know

 

[OakMoon!]

Re: O'level Maths, Addmaths and Statistics help available he

@abcde: That's what I meant: a sarcastic comment, somewhat like a taunt. Yeah! Just check it thoroughly. Check the marks allocated to each question and see if you missed anything accordingly.

 

[OakMoon!]

Re: O'level Maths, Addmaths and Statistics help available he

Againnnnnnnn!! I started out with "Nibz you didn't have to do that" before Hamid Ali. Just letting you know

Lol! And now I stole your wind. You've got slow typing speed, as simple as that.

 

[abcde]

Re: O'level Maths, Addmaths and Statistics help available he

I guess all of my wind has been stolen now! Bas karo...

 

[Nibz]

Re: O'level Maths, Addmaths and Statistics help available he

Okay. I've deleted my post!

You didn't need to do that. Maybe, xhizor understood better reading your post than abcde's. It totally depends on the learner.
If you deleted it because of my post, I was just kidding.

Sorry for that!
No, certainly not! ( not because of your post)

 

[xhizors]

Re: O'level Maths, Addmaths and Statistics help available he

alright alright :x forget that wind here's another one
Q5 b (ii) http://www.xtremepapers.me/CIE/Cambridg ... _qp_21.pdf

 

[OakMoon!]

Re: O'level Maths, Addmaths and Statistics help available he

Take x as the number of workers that used only bus as a mean of transport. Hence, the number of workers who used only bicycle are equal to 2x.
x+2x+13+6+3+17+15=78
3x+54=78
3x=24
x=8

 

[xhizors]

Re: O'level Maths, Addmaths and Statistics help available he

Jazakallah khair

 

[xhizors]

Re: O'level Maths, Addmaths and Statistics help available he

Q12 , Q16 http://www.xtremepapers.me/CIE/Cambridg ... 6_qp_1.pdf anyone

 

[intelnehalem]

Re: O'level Maths, Addmaths and Statistics help available he

Q12:
Interior angle of the polygon =140;
Exterior angle = 180-140 = 40
Number of sides = 360/40 = 9

Since they are congruent polygons, ABD = 40 +40
=80

 

[intelnehalem]

Re: O'level Maths, Addmaths and Statistics help available he

Q16 :
It is a hexagonal prism . Therefore 6 planes of symmetry for the hexagon. However since it is a prism, there is another plane of symmetry (the 3d object- prism can be cut halfway through its length) So in conclusion, it has 7 planes of symmetry.
Upper bound of length = 50.5 cm
Least possible perimeter = 2(lower bound of length+lower bound of width) = 2(49.5+14.5) = 128 cm
Hope you understood this