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Maths exam IGCSE - HIGHER TIER - PAPER 3H AND PAPER 4H POST DISCUSSION.

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I'm pretty sure it was 3.6 large squares / 19 large squares which gave an answer of 18.9%. Is this what you mean when you say you got 18%?

I counted the little squares. There were 500 in total, and the region we were looking at was 90 little squares. 90/500 x 100 = 18%

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Reply 1001

Umackjiggles

Original post by Tazxx_xx

I counted the little squares. There were 500 in total, and the region we were looking at was 90 little squares. 90/500 x 100 = 18%

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but it doesn't make a difference whether you count the large or the small squares the answer is still the same surely?

Reply 1002

IGCSE

Answers i got:

last question: 2.5cm
histogram: 18% and 200 people

btw..... are u actually allowed to be posting the paper and then the answers or are u doing this secretly... so i wont tell others :colone:

Reply 1003

Code:7248

Original post by desslop

because the question says the volume of the cylinder without the spheres is 125/6 pi or something. So in the equation you have to add the volume of the cylinder to the volume of the spheres. So its something like pi r squared h = 125/6 pi + 4/3 pi r cubed * 2.

WHAT??? The question said "The volume of the space inside the cylinder, not occupied by the spheres, is 125/6 π cm3". I thought (and still think) that means "Volume unoccupied by the spheres" = "Volume without the spheres" = "Volume when there are no spheres" = "Total volume of the cylinder", WITHOUT the spheres. So I did "125/6 π = 4πr cubed". Yes, I think I made a mistake. They should have made it a little clearer to understand. How many marks do you think I'll get? :frown:

None i think.

Reply 1004

Tazxx_xx

Original post by Umackjiggles

but it doesn't make a difference whether you count the large or the small squares the answer is still the same surely?

I'm not sure. But counting the big squares gives you a decimal answer of 18.9, right? But counting the small squares gave an exact number

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Reply 1005

Tazxx_xx

Original post by Code:7248

None i think.

That's exactly what I did! :frown:

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Reply 1006

username963570

Original post by Umackjiggles

I'm pretty sure it was 3.6 large squares / 19 large squares which gave an answer of 18.9%. Is this what you mean when you say you got 18%?

no i mean i counted 90 squares and divided by 500 squares to get 18%, i didnt count the large squares, did the small ones. btw for the 2nd to last Q, x=8 ?

Reply 1007

Emsss

Original post by gabriel 41

Thank you for putting trust in me; give me a rating and here goes the blank (raw) copy of the paper (check a few posts from now and you'll find the paper). Kaur will solve it in the next few hours and we'll have our estimated grade boundaries as well as the answers

You are a great member. Thanks very much

Reply 1008

Umackjiggles

Original post by Tazxx_xx

I'm not sure. But counting the big squares gives you a decimal answer of 18.9, right? But counting the small squares gave an exact number

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sorry I posted the wrong thing, its 3.6/20 :smile:

which is 18%

Reply 1009

Emsss

Original post by yl95

So for that cubic graph question, in the working, I put 'draw x=5' even though I drew y=5 on the graph and wrote down the correct answer, would Edexcel deduct a mark?

No they wouldn't . You get a mark for drawing the line.
And then another for the solution
It was only two marks

Reply 1010

Emsss

Original post by H!story

Dude I swear the histogram question was something close to 20% and you get like 200 something people. The only possible way to calculate the percentage is by counting the squares which is really really stupid.

It's 18% and 200

Reply 1011

gabriel 41

Can someone please answer the question I asked on page 51!

Reply 1012

Tazxx_xx

Original post by Umackjiggles

sorry I posted the wrong thing, its 3.6/20 :smile:

which is 18%

Ah, ok then that will be fine. You'd still get all three marks

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Reply 1013

Code:7248

Original post by Tazxx_xx

That's exactly what I did! :frown:

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Hey I actually blame them for not being clear enough. if they would have written "THAT is not occupied by the spheres", I would have done it right. But, they way they wrote it, it means "WHEN not occupied by the spheres". I was hoping for an A*. :ashamed:

Reply 1014

username963570

Original post by gabriel 41

For this question I did volume of 2 spheres + volume of empty space = volume of cylinder. Please tell me whether this is right or wrong. :confused:

Because when I solved the equation like that I yet got r=2.5. So my method is right isn't it?

aha i dont know i totally failed the last question lol

Reply 1015

Emsss

Original post by Fas

no i mean i counted 90 squares and divided by 500 squares to get 18%, i didnt count the large squares, did the small ones. btw for the 2nd to last Q, x=8 ?

8 .. Or -1!!!

Reply 1016

Tazxx_xx

Does anyone know what page the answers to 4H were on?

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Reply 1017

Umackjiggles

Original post by gabriel 41

For this question I did volume of 2 spheres + volume of empty space = volume of cylinder. Please tell me whether this is right or wrong. :confused:

Because when I solved the equation like that I yet got r=2.5. So my method is right isn't it?

Think about it logically, the volume of the cylinder contains 2 spheres and empty space. Therefore the volume of the cylinder is equal to the volume of the 2 spheres plus the volume of the empty space.

Rearranged : Volume of cylinder - Volume of spheres = Volume of empty space.