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Mistake On Ordinary Level Maths??

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  • 06-06-2008 10:54pm
    #1
    Resi12
    Closed Accounts Posts: 1,034 ✭✭✭


    Well im not too sure, but i got really confused by Question 1(b)(ii).
    The train one it said:

    "On a day of very heavy rain her average speed on a 28 km section of the journey
    was reduced to 35 km/h.
    How long did this section of the journey take on that day?"

    Well if its average speed was 28km how was it REDUCED to 35km? Surely thats an increase?? I dunno maybe its just my terrible maths skills but i just wanna know anyway? Thanks o and heres the link for Maths Ordinary 2008 paper 1 if u just want a look! http://www.examinations.ie/archive/exampapers/2008/LC003GLP100EV.pdf


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    #2
    LizT
    Registered Users Posts: 29,089 ✭✭✭✭LizT


    no it means for the 28 km of the track the train's speed was 35 km per hour


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    #3
    RA253195370HK
    Closed Accounts Posts: 22 ✭RA253195370HK


    No it means the distance was 28km, not the speed...


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    #4
    Resi12
    Closed Accounts Posts: 1,034 ✭✭✭Resi12


    RA253195370HK wrote: »
    No it means the distance was 28km, not the speed...

    god i feel stupid now!!! Thanks anyway:D


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    #5
    BaRcOe
    Registered Users Posts: 1,164 ✭✭✭BaRcOe


    haha

    what you need is an early night!
    These kinda things happen late at night!


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    #6
    Dr.Millah
    Registered Users Posts: 582 ✭✭✭Dr.Millah


    I know how you feel man.
    I got pretty confused on that part of the test but got it right after a while.

    In question 5 i was convinced in part b that the sequence was wrong.
    a was 1 over 27

    and i thought it said the first term not the SUM of them was given by the forumla.

    Wasted a good 5 minutes before i re read the question as usual.


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    #7
    RA253195370HK
    Closed Accounts Posts: 22 ✭RA253195370HK


    I couldnt figure that one out. What was the common ratio between them? I got .1, .3, 1 but couldnt figure it out.

    I was probably doing it wrong but I got confused!


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    #8
    Kazbah
    Registered Users Posts: 764 ✭✭✭Kazbah


    T1 = 3/27 = 1/9
    T2 = 9/27 = 1/3
    r = T2 / T3
    (1/3) / (1/9) = 3


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    #9
    RA253195370HK
    Closed Accounts Posts: 22 ✭RA253195370HK


    Looks like I was doing it wrong but I think I got 3 as my answer anyway so Ill probably get something for it


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    #10
    Kazbah
    Registered Users Posts: 764 ✭✭✭Kazbah


    Find T1 and T2 by just subbing in for n.
    In a geometric sequence it means every term is multipled by the same common ratio to find the next term.
    To find the ratio divide any term by it's previous term so divide T2 by T1 to find r.

    If the terms are increasing the ration is greater than one (usually a whole number). If the terms are decreasing the ratio is less than one (usually expressed as a fraction)


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    #11
    muggyog
    Registered Users Posts: 724 ✭✭✭muggyog


    wat was k i got 8??


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    #12
    angelfire9
    Registered Users Posts: 2,226 ✭✭✭angelfire9


    Resi12 wrote: »
    Well im not too sure, but i got really confused by Question 1(b)(ii).
    The train one it said:

    "On a day of very heavy rain her average speed on a 28 km section of the journey
    was reduced to 35 km/h.
    How long did this section of the journey take on that day?"

    Well if its average speed was 28km how was it REDUCED to 35km? Surely thats an increase?? I dunno maybe its just my terrible maths skills but i just wanna know anyway? Thanks o and heres the link for Maths Ordinary 2008 paper 1 if u just want a look! http://www.examinations.ie/archive/exampapers/2008/LC003GLP100EV.pdf
    Just as a matter of interest the journey took 48 minutes correct?


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    #13
    Papercut
    Closed Accounts Posts: 60 ✭✭Papercut


    The stretch of 28km took 48 mins.......that day the entire journey took 1Hr 45 mins.......anyone else get that???


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    #14
    IanCurtis
    Closed Accounts Posts: 1,004 ✭✭✭IanCurtis


    Yep
    35km/hour
    1km/(hour / 35)
    1km/1.71 minutes

    1.71minutes x 28km = 48 minutes

    WOOHOO I CAN DO JUNIOR CERT MATHS!!


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    #15
    Dr-Millie
    Closed Accounts Posts: 7 ✭Dr-Millie


    angelfire9 wrote: »
    Just as a matter of interest the journey took 48 minutes correct?

    Yeh i said that part took 48 mins, so her journey increased by ....umm 20 something minutes?? cant remember really. Thought it was a good paper, but only figured out wat N was in the last minute in sequences and series. Was it 7 yeh? was like "THANK GOD!!!"


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    #16
    darraghc
    Registered Users Posts: 17 ✭darraghc


    Kazbah wrote: »
    T1 = 3/27 = 1/9
    T2 = 9/27 = 1/3
    r = T2 / T3
    (1/3) / (1/9) = 3

    Don't you mean T3/T2 = R...
    The answer was 1/3!


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    #17
    Bryan4president
    Registered Users Posts: 123 ✭✭Bryan4president


    No the answer was 3. If the 1st term was 1/9 and the 2nd term was 1/3 then it was being multiplied by 3 every time. If it was a 1/3 then 2nd term would be 1/27.


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    #18
    louis626
    Registered Users Posts: 84 ✭✭louis626


    Bryan4president wrote: »
    No the answer was 3. If the 1st term was 1/9 and the 2nd term was 1/3 then it was being multiplied by 3 every time. If it was a 1/3 then 2nd term would be 1/27.


    yeah thats right...think i had that anyway lol:cool:


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    #19
    mattfender
    Closed Accounts Posts: 602 ✭✭✭mattfender


    Paper confused me a bit at times....

    Q1 C (ii) "The Retailer adjusts the price charged to the customer so that it is 1 cent less than a multiple of €10, while keeping the mark-up close as possible to 40%"


    How the HELL do you do that?!
    and for the greatest height in Q7 (c)(iii) was it 425m?
    Wrote down all my answers on the paper itself too...


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    #20
    irishbucsfan
    Registered Users Posts: 37,978 ✭✭✭✭irishbucsfan


    mattfender wrote: »
    Paper confused me a bit at times....

    Q1 C (ii) "The Retailer adjusts the price charged to the customer so that it is 1 cent less than a multiple of €10, while keeping the mark-up close as possible to 40%"


    How the HELL do you do that?!
    and for the greatest height in Q7 (c)(iii) was it 425m?
    Wrote down all my answers on the paper itself too...

    for Q1 C I cant remember the exact figures but the idea is...

    Say the retailer's original price was €123.49 (random number), what you had to do was adjust that to €119.99 (the closest number that is 1 cent less than a multiple of €10)

    and on Q7 C)(iii) I cant remember what I got, sorry


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    #21
    Dr.Millah
    Registered Users Posts: 582 ✭✭✭Dr.Millah


    mattfender wrote: »
    Paper confused me a bit at times....

    Q1 C (ii) "The Retailer adjusts the price charged to the customer so that it is 1 cent less than a multiple of €10, while keeping the mark-up close as possible to 40%"


    How the HELL do you do that?!
    and for the greatest height in Q7 (c)(iii) was it 425m?
    Wrote down all my answers on the paper itself too...

    I cant remember the figures anymore but i think what i did was right.

    The price was 123.40 euro or there abouts. then one cent less than multiple of ten would be 119.99 when i worked this out it was around a 32% mark up.

    I then used 129.99 and worked it out to be 40.67% to the nearest = 41%


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    #22
    chrissydeex
    Closed Accounts Posts: 3 ✭chrissydeex


    For question8 was d graph a U shaped graph or a 'squiggle' graph in the shape of a W sumwhat???


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    #23
    irishbucsfan
    Registered Users Posts: 37,978 ✭✭✭✭irishbucsfan


    chrissydeex wrote: »
    For question8 was d graph a U shaped graph or a 'squiggle' graph in the shape of a W sumwhat???

    there was supposed to be 2 curves. So an N i suppose


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    #24
    mattfender
    Closed Accounts Posts: 602 ✭✭✭mattfender


    Dr.Millah wrote: »
    I cant remember the figures anymore but i think what i did was right.

    The price was 123.40 euro or there abouts. then one cent less than multiple of ten would be 119.99 when i worked this out it was around a 32% mark up.

    I then used 129.99 and worked it out to be 40.67% to the nearest = 41%

    I would never have thought of that! It was too early in the morning for that type of stuff I think for me!


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    #25
    Kazbah
    Registered Users Posts: 764 ✭✭✭Kazbah


    darraghc wrote: »
    Don't you mean T3/T2 = R...
    The answer was 1/3!

    Typo I meant T2/T1 = 3
    3 is defo the answer.


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    #26
    Kazbah
    Registered Users Posts: 764 ✭✭✭Kazbah


    Q1 (a)138.75 (b)(i)68km/hr (ii)48mins
    Q1 biii 23 minutes (c)(i)E123.66 (ii)36%
    Q2(a)7 (b)(i)2+- sq 3 (ii)4 (c)(i)(x+2)(x+2)
    Q2 cii 2x + 3
    Q2 ciii 3
    Q3 a x = (8-5a)/a
    Q3 (b)(i)(5,4)(5,6) (c)(i)b=2 c=3
    Q3 bi (4, 3) (-3, -4)
    Q3 bii -5 or 9
    Q3 ci b=4 c=3
    Q3 cii 1
    Q4(a)(i)u=3-4i (ii)u+5i=3+i (b)(i)-21+20i (ii)29=29
    Q4 ci s=36 t=2
    Q5(a)95 (b)(i)one ninth (ii)3e (iii)t8
    Q5 biii k=7
    Q5 ci a=-15 d=2
    Q5 ci Tn = -17 + 2n
    Q5 cii n = 7 or 9
    Q7 ai 7x^6
    Q7 aii 5 - 12x^3
    Q7 bi -9x^2 -2x +12
    Q7 bii -16
    Q7 ci 405m
    Q7 cii 20m/s
    Q7 ciii 425m


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    #27
    darraghc
    Registered Users Posts: 17 ✭darraghc


    Kazbah wrote: »
    Typo I meant T2/T1 = 3
    3 is defo the answer.

    Yea sorry! I got 3 for my answer as well, just got a lil confused..my bad! Either way..twas a nice paper :D


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