2013 WESTLANDS MATHEMATICS P1 MS.pdf

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WESTLANDS FORM FOUR JOINT EVALUATION Kenya Certificate of Secondary Education MATHEMATICS Paper-121/1 ‘ July / August 2013 Marking Scheme a- V108 x 147 x lO- 4 0.21 x 4.8 V2x2x3x3x3x3x7x7x 10~ 4 0.21 x 4.8 2x3x3x7x 10" 2 0.21x4.8 2x3x3x7x 10 1 3x7x2x2x2x2x3 10 1 T “ 1 4 Ml Ml A1 3 2. x + y ~ 10 lOy +• x (lOx 4- y) ~ 54 9y — 9x = 54 9y + 9x — 90 18y = 144 y = 8,x = 2 TTie number is 28 Ml Ml A1 3 10 1 1 3 3 x 174..3i x 3:752 .J 100 8.5035 30 x 0.2665 ■ — 10 7.995 - 0.85035 7.14465 Ml Ml A1 3 4 10-4 6 3 = 3 - -- 7 = 10 = 5 5 m2 = — - /—7 4- 3 10 + 4\ m( 2 , 2 )-(-W y — 7 5 x - -2 3 (y - 7) = - - (x + 2) 5 19 y ~ —~x + -— * 3 3 Ml 81 Ml A 1 - 4 5 . 9 5 + 2 1 5 + 180(n - 4) = 180n - 360 150n -90 = 180n - 360 3 On = 270 n = 9 85 + 65 + (n - 2)30 = 360 Ml Ml A1 Accept alt two

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Transcript of 2013 WESTLANDS MATHEMATICS P1 MS.pdf

Page 1: 2013 WESTLANDS MATHEMATICS P1 MS.pdf

WESTLANDS FORM FOUR JOINT EVALUATIONKenya Certificate of Secondary Education

MATHEMATICS Paper-121/1 ‘

July / August 2013 Marking Scheme

a- V108 x 147 x lO-4

0.21 x 4.8 V 2 x 2 x 3 x 3 x 3 x 3 x 7 x 7 x 10~4

0.21 x 4.8 2 x 3 x 3 x 7 x 10"2

0.21x4.8 2 x 3 x 3 x 7 x 1 0 1

3 x 7 x 2 x 2 x 2 x 2 x 3 10 • 1

T “ 14

M l

M l

A 1

32. x + y ~ 10

l O y + • x — (lOx 4 - y ) ~ 5 4 9 y — 9 x = 5 4

9y + 9x — 9 0 1 8 y = 1 4 4 y = 8, x = 2

TTie number is 28

Ml

Ml

A13

10 1 1 3 3 x 174..3i x

3:752 .J 1008.5035

30 x 0.2665 ■ — 10

7.995 - 0.850357.14465

Ml

Ml

A1

34 1 0 - 4 6 3

= 3 - -- 7 = 1 0 = 55

m2 = — - / — 7 4 - 3 1 0 + 4 \

m ( 2 , 2 ) - ( - W y — 7 5 x - - 2 3

( y - 7 ) = - - ( x + 2 )5 1 9

y ~ —~x + -—* 3 3

M l

8 1

M l

A 1

-

45 . 9 5 + 2 1 5 + 180(n - 4) = 180n - 360

150n -90 = 180n - 360 3 On = 270

n = 985 + 65 + (n - 2)30 = 360

Ml

MlA1

Accept alt two

Page 2: 2013 WESTLANDS MATHEMATICS P1 MS.pdf
Page 3: 2013 WESTLANDS MATHEMATICS P1 MS.pdf

1Z. 1cm = 2km 1cm2 = 4fem2

11.7cm2 = 11.7 x 4 = 46.8km2 Area in hectare = 46.8 x 100

= 4680 ha

M7

Ml

A

changing linear scale factor into A.S.F getting actual area.

313. Sin (3^r — 50) = cos(2x + 10)

Sin (3x - 50) - Sin (90 - (2x + 10)3x — 50 + 2x + 10 = 90

5x = 130 x = 26°

MiMlA1

Complementary angles droppy x near cosine

3

14. 20 B — = tan 62X

20X tan 62

f

64\ t

Ml

MlA1

Correct substitution

Attempt to solve forxX —- iU.OJ Tfl X

3

15. i?2 — r2 — 100

Area = n{R2 — r2) = 100x3.142 = 314.2cm2

1

B1

MlA1

Method and answer (Pythagoras theorem) Substitution

316. lOOp + 800p + 200p = 22000

HOOp = 22000 200 x 20

p - 2 0 “ - 4 0 0 = 1 0

Total = 10 + 20 + 80 = 110

M l

A1

B 1

Formation of equation

3

17.a)h 4 9 = 64

h = — x 9 = 6 cm 6

i 2 2 , , ^ K = -x — x 4 x 4 x 6 3 7

4VoJ. = 100-cm3

M1

A1

M1

A1

Correct expression

Substitution in correct formula

b ) 7r x 4 x 4 x h = x 4 x 4 x 6 M1 equating

c )

/i = 2height of water — 12 — 2 = 10cm2

1FoZ. = 7 r x 4 x 4 x l Q — —7r x 6 x 6 x 9

= 1607T - 1087122 3 33 = 52 x — = 163 —cm33

A1

B1

M1M1A1

correct expressions substraction

10

- ’

- ' &

I 11 u/etctt ampiq . chrm A - MATHEMATICS - 1

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18.

19a)

b)

c)

d)

520 xSin 32 ” Sin 118

520 sin 118* = Sin 32

= 866.32 m

= Cos32866.42

x — 866.32 cos 32 = 750m

Height = 750 tan 30

= 433m

—— = tan 80433

76.37tan 80

Distance = 750 — 76.37 - = 673.6m

x3 — 9x — 0 x(x2 - 9) = 0

x .= 0 or x = ±3

X -3 -2 | -1 0 i 2 3

y 0 O 00 0 -8 ,10 I 0

Area — — x 1{0 + 0 + 2(10 + 8 + 0 + 8 + 10)}2 ^

1Area = - x 2 x 36 = 36 sq units

2

o *Area = J(x3 - 9x)dx + f (x3 - 9x)dx

n 4 9I aX ~ nL4 2

X2 + c3

■»0

= 20.25 + -20.25= 40.5 sq unit

Error — 40.5 — 36 = 4.5

4.5Percentage Errors -

Ml

Ml

A1

Ml

A1

Ml

Al

Ml

Ml

Al

Sine rule with correct substitution attempt to solve forx

substitution

substitution

substitution

10M1A1

B1

M1

A1

M1

M1

A1

ordinates

Substitu for the coorindate

intergral expression substities in the integrated expression

<B 70n WSSTI.ANDS- FORM 4 - MATHEMATICS - I

Page 5: 2013 WESTLANDS MATHEMATICS P1 MS.pdf

20a)Det = 4x5 — 6x3 = 20 — 18

) = f2 “L5) J V-3 2.5 )Inverse1, 4 -3 2 '—6 5

b) (:2.55) (6

2 ) ® - ' 8 4 0 'V1040/3\(x\ _ ( 2 —1.5\ / 840 'N 4/ \yJ V—3 2.5 ) \1040'

?)©=©X =e 120,3/ = 80

Small costs = Sh, 80, Large costs 120

Large = -y-rz X 120 = 144

CoSh. 120

c)100

90Small =? x 80 = 72

« <424)

1152 4- 360 = Sh. 1,510

M1

,A1

B1M1

M1

A1

M1M1M1

A1in

^ ( - 6 1 )

matrix equation

premultiplication both sides

attempt to solve

both x cost of large and small

- ZDAB=35°Alternate segment theorem

b) ZADB=55°The radius and the tangent are perpendicular

c) Z EOD=70°Angle at the centre is twice the angle at the circumference

d) Z DCB=62°Angle in a semi circle is right angled

e) AFE=145 . ^Opposite angles of acyclic quadrilateral are suplimetary

B1B1

B1B1

, B 1B 1

B1B1

B1B1

Mark for the correct angle

One mark for the season

1022"

Class 10.5-20.5 20.5-25.5 25.5-40.5 40.5-50.5 50.5-55. 5i 10 5 15 10 5fd 1.2 2.6 1.4 2.2 1.2f 12 13 21 22 6

b)Modal frequency = 22

B1B1B2

B1

class width frequency densityall correct frequencies B1 - any 4 correct

modal frequency

Page 6: 2013 WESTLANDS MATHEMATICS P1 MS.pdf

B1 modal frequency

Class i fd X f x-A fd10.5-20.5 10 1.2 15.5 12 -17.5 -21020.5-25.5 5 2.6 23 13 -10 -130

25.5-40.5 15 1.4 33 21 0 0

40.5 - 50.5 10 2.2 45.5 22 12.5 27550.5 — 55.5 5 1.2 53 6 20 20

Total 74 55

Mean = 33 +5574

Mean = 33 4- 0.7432 = 33.7432

B 1

B1

B1

Ml

Al

W

mid - poin

deviations from assumed mean - (d)

fd

correct

23. 7̂ 27

(_88)

^=I(-88) = (-66)

m-i , )= (“ )D(10,-4)

^=e° 4) - l c 26)

™ - a - (-42)

=(-2)

Ml

Al

B1

Ml

Al

B1

Ml

A1

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ND = J62 + (—2)2 = V40 ND = 6.325 units

* Time taken — %

Time — 8.40 + 2.00 = 10.30am

M1

A1

10

60 80 VII80x — 3200 = 60x y[|

20x = 3200 Vfl.r — 160fcm

320 - 160 = 160/cm

160 uriTime taken = -r-r- = 2 hrs »80

Bus took = 200 = 3 hrs, 20 mins M1 W~

Saloon took = 200 = 2hrs, 30 mins M1 TRT

Repair time = 3hr 20min - 2 hrs 30 mins M1= 50 min A1

"

Marking Scheme 7 0 2013 WESTLANDS - FORM 4 - MATHEMATICS -1