Upload
henry-hawkins
View
213
Download
0
Embed Size (px)
Citation preview
8/3/2019 5540H_4H_rms_20080814
1/20
Edexcel GCSE
Mathematics 2540
Paper 5540H/4H
Mark Scheme
Summer 2008Mark Scheme
Mark Scheme ( Results)
matics
2540
8/3/2019 5540H_4H_rms_20080814
2/20
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If working is crossed out and still legible, then it should be given anyappropriate marks, as long as it has not been replaced by alternativework.If there is a choice of methods shown, then no marks should beawarded, unless the answer on the answer line makes clear themethod that has been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
8/3/2019 5540H_4H_rms_20080814
3/20
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.
8/3/2019 5540H_4H_rms_20080814
4/20
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
8/3/2019 5540H_4H_rms_20080814
5/20
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.
8/3/2019 5540H_4H_rms_20080814
6/20
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)
8/3/2019 5540H_4H_rms_20080814
7/20
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)
8/3/2019 5540H_4H_rms_20080814
8/20
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)
8/3/2019 5540H_4H_rms_20080814
9/20
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)
8/3/2019 5540H_4H_rms_20080814
10/20
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
8/3/2019 5540H_4H_rms_20080814
11/20
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
8/3/2019 5540H_4H_rms_20080814
12/20
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
8/3/2019 5540H_4H_rms_20080814
13/20
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
8/3/2019 5540H_4H_rms_20080814
14/20
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
8/3/2019 5540H_4H_rms_20080814
15/20
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
8/3/2019 5540H_4H_rms_20080814
16/20
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
8/3/2019 5540H_4H_rms_20080814
17/20
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
8/3/2019 5540H_4H_rms_20080814
18/20
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
8/3/2019 5540H_4H_rms_20080814
19/20
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
8/3/2019 5540H_4H_rms_20080814
20/20
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