5540H_4H_rms_20080814

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    Edexcel GCSE

    Mathematics 2540

    Paper 5540H/4H

    Mark Scheme

    Summer 2008Mark Scheme

    Mark Scheme ( Results)

    matics

    2540

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    NOTES ON MARKING PRINCIPLES

    1 Types of markM marks: method marksA marks: accuracy marksB marks: unconditional accuracy marks (independent of M marks)

    2 Abbreviationscao correct answer only

    ft follow throughisw ignore subsequent workingSC: special caseoe or equivalent (and appropriate)dep dependentindep - independent

    3 No working

    If no working is shown then correct answers normally score full marksIf no working is shown then incorrect (even though nearly correct)answers score no marks.

    4 With workingIf there is a wrong answer indicated on the answer line always checkthe working in the body of the script (and on any diagrams), and

    award any marks appropriate from the mark scheme.If it is clear from the working that the correct answer has beenobtained from incorrect working, award 0 marks. Send the responseto review, and discuss each of these situations with your TeamLeader.Any case of suspected misread loses A (and B) marks on that part, butcan gain the M marks. Discuss each of these situations with yourTeam Leader.

    If working is crossed out and still legible, then it should be given anyappropriate marks, as long as it has not been replaced by alternativework.If there is a choice of methods shown, then no marks should beawarded, unless the answer on the answer line makes clear themethod that has been used

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    6 Ignoring subsequent workIt is appropriate to ignore subsequent work when the additional work

    does not change the answer in a way that is inappropriate for thequestion: eg. incorrect cancelling of a fraction that would otherwisebe correctIt is not appropriate to ignore subsequent work when the additionalwork essentially makes the answer incorrect eg algebra.Transcription errors occur when candidates present a correct answerin working, and write it incorrectly on the answer line; mark the

    correct answer.

    7 ProbabilityProbability answers must be given a fractions, percentages ordecimals. If a candidate gives a decimal equivalent to a probability,this should be written to at least 2 decimal places (unless tenths).Incorrect notation should lose the accuracy marks, but be awardedany implied method marks.

    If a probability answer is given on the answer line using bothincorrect and correct notation, award the marks.If a probability fraction is given then cancelled incorrectly, ignore theincorrectly cancelled answer.

    8 Linear equationsFull marks can be gained if the solution alone is given on the answer

    line, or otherwise unambiguously indicated in working (withoutcontradiction elsewhere). Where the correct solution only is shownsubstituted, but not identified as the solution, the accuracy mark islost but any method marks can be awarded.

    9 Parts of questionsUnless allowed by the mark scheme, the marks allocated to one partof the question CANNOT be awarded in another.

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    5540H/4H

    Question Working Answer Mark Notes

    1 (a) 5

    12

    2M1 for

    12

    nor 12n or

    543 ++

    nor

    )543( ++n where n is an integer12

    A15

    12or 0.41(6) or 41.6%

    (b) 1 512

    712

    1 B1 ft 1- 512

    provided the answer is

    positive, or7

    12or 0.58(3)

    2 22.4 14.5 = 324.8

    8.5 3.2 27.2

    11.94117647 2M1 for 324.8 or 27.2 or

    5

    1624or

    5

    136

    A1 11.941(17647) Accept17203 , 11

    1716

    3 (a) Points plotted 1 B1 points plotted 1 full smallest square

    tolerance.

    (b) Negative 1 B1

    (c) lobf 1 B1 lobf that goes between (8,2000) and

    (8,2400) and between (24,0) and (24,500)(d) 11-13 1 B1 11-13 or ft (tol 1 square) from single

    straight line segment with a negative gradient

    (e) 850-1150 1 B1 850-1150 or ft (tol 1 square) ) from

    single straight line segment with a negative

    gradient

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    5540H/4H

    Question Working Answer Mark Notes

    4 58

    Reason

    2 B1 cao

    B1 (dep) alternate or Z angle (oe)

    5 Sketch 2 B2 complete 3-D sketch

    (B1 for partial 3-D sketch e.g. pyramid only)

    (B1 for partial 3-D sketch e.g. pyramid or

    base only, or a shape with a box and 2pyramids either end)

    Accept hidden lines as dashed or solid

    NB: If more than one shape is shown:

    For 2 marks there should be no choices or

    alternatives other than those also worth 2

    marks; if there are several diagrams of which

    at least one is worth 1 or 2 marks, award B1.

    2D diagrams get B0.

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    5540H/4H

    Question Working Answer Mark Notes

    6 3n+2 2 B2 for 3n+2 (oe, including unsimplified)

    (B1 for 3n+k, k2)

    7 2 12

    3 33 2.5 20.(625)

    2.1 13.(461) 2.6 22.(776)2.2 15.(048) 2.7 25.(083)

    2.3 16.(767) 2.8 27.(5(52)

    2.4 18.(624) 2.9 30.(189)

    2.73 25.8(06) 2.74 26.0(508) or 26 2.75 26.2(96) 2.76 26.5(45)

    2.7 4 B2 for trial between 2.7 and 2.8 inclusive

    (B1 for trial between 2 and 3 inclusive)

    B1 for different trial between 2.73 and 2.75inclusive

    B1 (dep on at least one previous B1) for 2.7 only

    NB trials wherex has 1 d.p should be rounded or

    truncated to at least 2SF; trials wherex has 2 d.p.

    or moreshould be rounded or truncated to at

    least 3SF

    8 Points at (5, 4), (15.5, 13), (25.5, 17), (35.5, 19),

    (45.5, 7)

    Polygon 2 B2 Complete polygon (ignore histograms and

    any lines below a mark of 5 or above a mark of

    45, but award B1 if there is a line joining the first

    to last point)

    (B1 One vertical or horizontal plotting error OR

    incorrect but consistent error in placing the

    midpoints horizontally OR correct plotting but

    not joined. In this case ignore a line joining firstto last)

    Plotting tolerance : half square

    Points to be joined by lines (ruled or hand-

    drawn, but not curves)

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    5540H/4H

    Question Working Answer Mark Notes

    9 (a) 2x+2x+x+10+50=360 5x+60

    =360

    2 M1 3 or 4 out of 2x, 2 x,x + 10, 50 added

    together

    A1 2x+2x+x+10+50 = 360 oe includingx =60

    (b) 5x+60=360

    5x=300

    60 3 M1 for isolating their terms inx

    M1 for dividing their numerical term by the

    coefficient of theirx term

    A1 caoAll the marks in (b) may be given for work done

    in answering (a) providing there is no

    contradiction

    Candidates can score full marks in (b)

    independent of their answer in (a) (e. g. by

    starting again)

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    5540H/4HQuestion Working Answer Mark Notes

    10 (a) 45 2 9 10 2 M1 for 45 "72" + or 45 2 or 5 seen, or 90seen or 10 seen as part of a ratio e.g 10:35

    A1 cao

    (b)

    (80 17.5/100) + 80 = 14 + 80 =

    94 3M2 for

    100

    5.11780 or 80 1.175 oe

    A1 caoor

    M1 for 80 0.175 or100

    5.1780 oe or 14 seen

    or 8 + 4 + 2 seen

    M1(dep) 14 + 80 or 80 +100

    5.1780 oe

    A1 cao(c) 12000 0.82

    OR

    1st yr: 12000 0.2 = 2400; 12000 2400 = 9600

    2nd yr: 9600 0.2 = 1920; 9600 1920 = 7680

    [3rd year is 6144; 4th yr is 4915.20]

    7680 3 M2 for 12000 0.82 or 12000 0.83

    A1 cao

    ORM1 12000 0.8 oe or 9600 or 2400 or 4800

    or 7200 seen

    M1(dep) 9600 0.8 oe

    A1 cao

    (if correct answer seen, ignore extra years)

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    5540H/4HQuestion Working Answer Mark Notes

    11 (a) 2a+4c 1 B1 2a+4c or 2(a +2c)

    (b) (3)2 = 9 = 1.125 1.125 2 M1 for substitution: 32 oe

    A1 1.125, 18

    1,

    8

    9oe

    (c) x(x-5) 2 B2 , accept )5( +xx

    (B1 forx(linear expression inx) orx-5 seen)(d) x

    2 + 3x + 4x + 12 x2+7x+12 2 B2 for fully correct

    (B1 for 3 out of 4 terms correct in working

    including signs, OR 4 terms correct, with

    incorrect signs).

    (e) (y+3)(y+5) 2 B2 for fully correct

    (B1 for ))(( byay ++ with one ofab = 15,

    a+b = 8)

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    5540H/4HQuestion Working Answer Mark Notes

    12 (a) 91 85 6100 100

    85 85

    = = 7.05882..

    7.06% 3M2 100

    85

    8591

    (M191 85

    85

    or sight of

    6

    85or 0.0705

    0.071 or 85

    91or 1.0705 1.071)

    A1 7.05 7.06

    Or

    M1 10085

    91 (=107.05)

    M1 (dep) 107.05 -100A1 7.05-7.06

    T&I methods must lead to an answer 7.05

    7.06 for full marks, otherwise 0 marks

    (b) (64+73+85)/3 = 222/3 = 74

    (73+85+91)/3 = 249/3 = 83

    74, 83 2 M1 for (64+73+85)/3 or (73+85+91)/3 or

    222/3 or 249/3 or 74 or 83 (condone missingbrackets)

    A1 both answers in the correct order cao

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    5540H/4HQuestion Working Answer Mark Notes

    13 (a) 42 10 = 502.65(502-503)

    503 2 M1 42 10 (=502.65)A1 502-503

    SC B1 82 10(b) 502.65 0.6 = 301.59 302 2 M1 502.65 0.6

    A1 300 302 ft on 502.65 to an answer

    which would be correct on ft if rounded ortruncated to 3SF

    14 (a) 7 8 = 56 = 28 28 2M1 7 8 or

    2

    1 7 8 sin 90o

    A1 cao

    (b) 82 + 72

    64 + 49 = 113113 = 10.630145

    10.63 3 M1 82 + 72 or 64+49 or 113

    or 8

    2

    + 7

    2

    90cos872

    M1 (64+49) or113 where it is clearthat the 8 and 7 have been squared

    A1 Any answer in 10.63 10.631 inclusive

    SC B1 10.6 with no working with or without

    a scale drawing

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    5540H/4HQuestion Working Answer Mark Notes

    (c) tany = 32/46 = 0.6956

    tan-1 0.6956 = 34.82

    34.8 3M1 tan (y = )

    46

    32

    M1 tan-1 0.695(6) or tan-1

    46

    32or tan-1

    46

    32oe

    (e.g.shift tanor inv tanfor tan-1)

    A1 34.79 34.85o

    Or

    M1 for )4632( 22 + (=56.03(5..)) and either

    32

    sin

    ..)0.(56

    90sin y= or

    ysin

    32

    90sin

    ..)0.(56=

    M1

    ..)06(571.0(sin(...)0.(56

    90sin32sin)( 11 =

    =y

    A1 34.79 34.85o

    SC1 B2 Radians 0.607-0.608

    B2 Gradians 38.65 38.7

    (both using tan)

    Alternative methods using Pythagoras andthen sin or cos must have a fully correct

    method for Pythagoras and sin/cos before

    they score the first M1. The trigonometry

    could be SOHCAHTOA or Sine rule/Cosine

    rule

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    5540H/4HQuestion Working Answer Mark Notes

    15

    B at ( 2, 1), ( 4, 1)

    ( 2, 4)

    C at (4, 1), (6, 1), (4, 4)

    Rotation

    180

    about (1,0)

    3 B1 for rotation

    B1 for 180

    B1 for centre (1,0)

    OR

    B1 Enlargement

    B1 Scale Factor1 Accept 1 on its own if it

    is clear candidate is describing an enlargement

    B1 Centre (1,0)

    Ignore diagram unless no marks scored, in

    which case

    SC B1 for showing both B and C correctly

    NB Award no marks for the description if more

    than one transformation is given

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    5540H/4HQuestion Working Answer Mark Notes

    16 (a) 2)252

    2)126

    3) 63 or factor trees

    3) 21

    7) 7

    1

    22337 3 M1 for attempt at continual prime factorisation(at least 2 correct steps); could be shown as a

    factor tree

    OR sight of at least one each of 2, 3, 7 as

    factors of 252

    A1 for a fully correct factor tree or 2, 2, 3, 3, 7which may include 1, but no other numbers

    A1 22337 or 22327 oe(b) HCF: The numbers must be 3n

    and 3m where n and m are

    coprime and at most one is a

    multiple of 3

    LCM: Factors of 45 are 1, 3, 5,

    9, 15, 45

    9 and 15

    or 3, 45

    3 B3 cao

    (B2 for 2 numbers with HCF of 9 or LCM of

    15)

    (B1 for any attempt to list any 4 factors of 45 or

    any 4 multiples of 3).

    17 20 1.51 1026 3.021027 2 M1 20 1.51 1026 or 3.02 10n

    or 30.21026

    where n is a positive integer

    A1 cao

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    5540H/4H

    Question Working Answer Mark Notes18 Region

    indicated

    3 M1 Bothx=2 drawn from at least (2,1) to (2,4)

    and y= 1 drawn from at least (2,1) to (5,1)

    M1 forx+y = 6 drawn from at least (2,4) to

    (5,1)

    A1 Correct region indicated by shading or

    clearly labelled. Boundaries of the region may

    be solid or dashed.

    19 2150 13360

    = 9291585.530641.0.

    = 221.22

    221 2M1 for 2

    15013

    360 or 4.2132 oe

    A1 220 - 222

    20 (a) q = k ; 8.5 = k

    t2 42

    k= 8.5 42; k= 136

    q = 136

    t2

    3 M1 q = k, (k 1 )t2

    M124

    5.8k

    =

    A1 cao

    NB q = k in the answer line followed by k

    t2

    being found correctly anywhere in (a) or (b)

    earns all 3 marks

    (b) q = 136 52 = 136 25 5.44 1

    B1 ft for25

    '136'oe

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    5540H/4HQuestion Working Answer Mark Notes

    21 (a)

    Freq = FD int width = 0.018 1000 = 18

    Or = 18 1 = 18

    = 0 .010 2000 = 20 or 10 2 = 20

    = 0.006 2000 = 12 or 6 2 = 12

    OR

    No of small squares = 200 Total freq = 16

    So 1 small square = 16 200 = 0.08

    9 25 0.08 = 18

    10 25 0.08 = 20

    6 25 0.08 = 12OR 8 cm2 = 16 so 1 cm2 = 2 etc

    18,20,12 2 M1 use of Freq = FD int width

    or attempt to find freq of 1 standard square

    (or one answer correct)

    A1 cao: all three

    (b) FD = Freq int width = 16 2000 = 0. 008 so

    4 sqs up

    = 8 4000 = 0.002 so 1 sq up

    OR

    16 0.08 = 200 200 25 = 8 so 4 sqs up8 0.08 = 100 100 25 = 4 so 1 square up

    OR 16 2 = 8 so 4 sqs up etc

    4000-6000

    4 cm high

    8000-12000

    1 cm high

    2 B1 4000-6000; 4 cm high

    B1 8000-12000; 1 cm high

    or

    if B0, M1 use of Freq = FD int width

    or attempt to find freq of 1 standard square

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    5540H/4HQuestion Working Answer Mark Notes

    22 238 has an UB 238.5, a LB of 237.5

    27.3 has an UB of 27.35, a LB of 27.25

    Upper: 238.5 = 8.75229

    27.25

    8.75 3 B1 for one of 238.5, 237.5, 27.35, 27.25,

    94.238 ,

    934.27 seen

    M1 for UB no of milesLB no of litresWhere 238< UB no of miles238.5 and27.25 LB no of litres

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    5540H/4HQuestion Working Answer Mark Notes

    23 (a) 5(x 1)=(4 3x)(x + 2)

    5x 5 = 4x + 8 3x2 6x (= 2328 xx )(3x

    2+ 6x + 5x 4x 5 8 = 0)

    3x2 + 7x 13 = 0

    Proof 3 M1 multiply through by )2)(1( + xx and

    cancel correctlyM1 expand 5(x 1 ) and (4 3x)(x + 2)

    correctly, need not be simplified

    A1 rearrange to give required equation (dep

    on both Ms and fully correct algebra)(b) a = 3, b = 7, c= 13

    x=-7(72+4313) = -7(49+156) = -72056 6 6

    x = 1.2196 or 3.55297.

    Or

    03

    13

    6

    7

    6

    722

    =

    +x

    3

    13

    6

    7

    6

    72

    +

    =

    +x

    x = 1.2196 or -3.55297.

    1.22

    -3.55

    3 M1 correct substitution in formula ofa = 3, b

    = 7 and c = 13

    M1 reduction to6

    2057

    A1 1.215 to 1.22 and 3.55 to 3.555

    Or

    M1

    2

    6

    7

    +x

    M136

    205

    6

    7

    A1 1.215 to 1.22 and -3.55 to -3.555

    SC T&I 1 mark for 1 correct root, 3 marks for

    both correct roots

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    5540H/4HQuestion Working Answer Mark Notes

    24

    10122

    151012cos

    222

    +=x =

    240

    19

    x = cos-1 0.079 = 85.459

    OR

    152 = 122 + 102 21210cosx

    cosx = 152 122 102 = 122 + 102 152 = 19

    -21210 21210 240

    x = cos-1 0.079 = 85.459

    85.5 3M2

    10122

    151012cos

    222

    +=A

    A1 85.4 -85.5

    OR

    M1 correct substitution into

    Abccba cos2222 += M1 correct rearrangement of

    Abccba cos2222 += algebraically to

    cb

    acbA

    +=

    2)(cos

    222

    oe

    or to

    (cosA =)10122

    151012 222

    +

    oe

    These can be earned in either order

    A1 85.4-85.5

    SC B2 Radians 1.49 seen

    B2 Gradians 94.89-95 seen

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    5540H/4HQuestion Working Answer Mark Notes

    25 7 = ka1 ; 175 = ka3

    k= 7 , 175 = 7a3 , 175 = 7a

    2

    a a

    a2 = 25, so a = 5, k=1.4

    Or3333

    175,7 kaak ==

    175

    732 =k , k=1.4, a = 5

    k= 1.4

    a = 5

    3 M1 eithera2 = 25

    or 7 = ka (or 7 = ka1) and 175 = ka

    3

    A1 k= 1.4 oe

    A1 a = 5

    SC Eithera = 5 ork= 1.4 oe gets B2