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Author Topic: Additional Math Help HERE ONLY...!  (Read 76050 times)

Offline BlackBunny103

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Re: Additional Math Help HERE ONLY...!
« Reply #375 on: June 09, 2010, 11:58:14 am »
Quote from: J.Darren on June 09, 2010, 11:56:14 am
Yup I recalled the question, I am guessing that P2 is going to be easy as all the hard topics were featured in yesterday's paper ...

By the way what did you got for OC ?

I actually forgot what I got for OC. :P What did you get? Perhaps, it'll jog my memory a bit.
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Offline J.Darren

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Re: Additional Math Help HERE ONLY...!
« Reply #376 on: June 09, 2010, 11:59:17 am »
Quote from: Deniz on June 09, 2010, 11:57:23 am
A student has a collection of 9 CDs, of which 4 are by the Beatles, 3 are by Abba and 2 are by the
Rolling Stones. She selects 4 of the CDs from her collection. Calculate the number of ways in which
she can make her selection if
(i) her selection must contain her favourite Beatles CD, [2]
(ii) her selection must contain 2 CDs by one group and 2 CDs by another.


can some1 explain how to solve this question?
i) 5C3 * 4C1

ii) 2 Rolling Stones + 2 Others

2C2 * 7C2

2 Beatles + 2 Others

4C2 * 5C2

2 Abba + 2 Others

3C2 * 6C2

Add them all together.
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Offline J.Darren

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Re: Additional Math Help HERE ONLY...!
« Reply #377 on: June 09, 2010, 11:59:47 am »
Quote from: BlackBunny103 on June 09, 2010, 11:58:14 am
I actually forgot what I got for OC. :P What did you get? Perhaps, it'll jog my memory a bit.
I got 63 subtracted by something for i ...
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Offline BlackBunny103

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Re: Additional Math Help HERE ONLY...!
« Reply #378 on: June 09, 2010, 12:01:36 pm »
Quote from: J.Darren on June 09, 2010, 11:59:47 am
I got 63 subtracted by something for i ...

Yesh ;D, I remember getting 63j - _i what I've forgotten ;D YAY
Which part did you choose for Q12? I went for the second one, it was so easy.
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Offline J.Darren

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Re: Additional Math Help HERE ONLY...!
« Reply #379 on: June 09, 2010, 12:03:10 pm »
Quote from: BlackBunny103 on June 09, 2010, 12:01:36 pm
Yesh ;D, I remember getting 63j - _i what I've forgotten ;D YAY
Which part did you choose for Q12? I went for the second one, it was so easy.
Most of my mates did EITHER. I did EITHER as well ... however it seems that virtually everyone has gotten a negative answer for area under the curve :o
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Offline BlackBunny103

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Re: Additional Math Help HERE ONLY...!
« Reply #380 on: June 09, 2010, 12:04:49 pm »
Quote from: J.Darren on June 09, 2010, 12:03:10 pm
Most of my mates did EITHER. I did EITHER as well ... however it seems that virtually everyone has gotten a negative answer for area under the curve :o

At my school, there are some did EITHER & some did the second part. For EITHER, how is that possible? I mean area can't be negative, that's a fact :-\
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Offline SAKS10111

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Re: Additional Math Help HERE ONLY...!
« Reply #381 on: June 09, 2010, 12:06:03 pm »
Quote from: J.Darren on June 09, 2010, 12:03:10 pm
Most of my mates did EITHER. I did EITHER as well ... however it seems that virtually everyone has gotten a negative answer for area under the curve :o

ok i did EITHER and i did not get a negative answer. i got a weird answer it was like in pi and stuff. final answer was in decimals. does anyone remember what they got for the answer?
also, what did everyone get for the permutations/combinations questions (variant 2)
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Offline Deniz

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Re: Additional Math Help HERE ONLY...!
« Reply #382 on: June 09, 2010, 12:07:05 pm »
Quote from: J.Darren on June 09, 2010, 11:59:17 am
i) 5C3 * 4C1

ii) 2 Rolling Stones + 2 Others

2C2 * 7C2

2 Beatles + 2 Others

4C2 * 5C2

2 Abba + 2 Others

3C2 * 6C2

Add them all together.

in the answer sheet, the answer of (i)is 56. i reckon u r wrong?
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Offline BlackBunny103

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Re: Additional Math Help HERE ONLY...!
« Reply #383 on: June 09, 2010, 12:08:16 pm »
Quote from: SAKS10111 on June 09, 2010, 12:06:03 pm
also, what did everyone get for the permutations/combinations questions (variant 2)

That permutation & combination question was so easy. I remember neither the question nor my answers lolz, but found it easy. What were your answers? This should bring back my goldfish memory ;D
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Offline SAKS10111

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Re: Additional Math Help HERE ONLY...!
« Reply #384 on: June 09, 2010, 12:11:51 pm »
Quote from: BlackBunny103 on June 09, 2010, 12:08:16 pm
That permutation & combination question was so easy. I remember neither the question nor my answers lolz, but found it easy. What were your answers? This should bring back my goldfish memory ;D

haha i have the same problem, i'll remember when someone else says the answer. um i remember the final answer being 20160 i think. don't remember the first two ones very well
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Offline xlane

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Re: Additional Math Help HERE ONLY...!
« Reply #385 on: June 09, 2010, 12:12:25 pm »
sum1 explain how to solve da 2nd n 3rd part of oct/nov 2002 p1..12 either..please
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Offline Ghost Of Highbury

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Re: Additional Math Help HERE ONLY...!
« Reply #386 on: June 09, 2010, 12:22:48 pm »
Quote from: xlane on June 09, 2010, 12:12:25 pm
sum1 explain how to solve da 2nd n 3rd part of oct/nov 2002 p1..12 either..please

ii) when theta = 30

R = r(1+1/sin 30) = 3r

Area of circle = pi*r^2

Area of sector = 1/2 R^2(pi/3) = (3pir^2)/2

fraction : pir^2/(3pir^2)/2 = 2/3

iii) tan 30 = r/d (R = 15 , 15 = 3r , r = 5)

    tan 30 = 5/d

d = 5/tan 30 = 8.66

arc length = r*a = 5(2pi/3) = 10.47

perimeter = 10.47 + 2(8.66) = 27.8
« Last Edit: June 09, 2010, 12:28:25 pm by Ghost Of Highbury~ »
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Offline xlane

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Re: Additional Math Help HERE ONLY...!
« Reply #387 on: June 09, 2010, 01:06:17 pm »
Thanks ghost o highbury..bt u r hardly a ghost..u can type n ur usin a modern technology :P
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Offline adrian1993

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Re: Additional Math Help HERE ONLY...!
« Reply #388 on: June 09, 2010, 01:31:00 pm »
Hmm, can someone who did variant 1 tell us what came out in their paper 1?

Yeah, the permutations question was so easy. I remember the last answer was 100 for that question.

I think relative velocity would probably come out tomorrow...
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Offline jellybeans

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Re: Additional Math Help HERE ONLY...!
« Reply #389 on: June 09, 2010, 02:33:40 pm »
OH, & for variant 2, the combination question for choosing 7 pieces from 6 classical & 4 modern pieces..
i got 10C7 = 120ways for i) and 100 ways for ii) :) :) did anyone get the same answers?
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