WRP Solutions General Mathematics 2012

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    WESTERN REGION

    2012Preliminary Final

    EXAMINATION

    General Mathematics

    SOLUTIONS

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    Preliminary Final Examination General Mathematics 2012

    Multiple Choice Answer Sheet

    Name ______________________________

    Completely fill the response oval representing the most correct answer.

    1. A B C D

    2. A B C D

    3. A B C D

    4. A B C D

    5. A B C D

    6. A B C D

    7. A B C D

    8. A B C D

    9. A B C D

    10. A B C D

    11. A B C D

    12. A B C D

    13. A B C D

    14. A B C D

    15. A B C D

    16. A B C D

    17. A B C D

    18. A B C D

    19. A B C D

    20. A B C D

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    Question 21 Final Preliminary Examination General Mathematics

    2012

    Part Solution Marks Comment

    (a) y = 2x

    6 or 2x

    y

    6 = 0 2 1 for correctgradient

    1 for correcty-intercept.

    (b) 2x15 = 3x4

    4(2x15) = 3x

    8x60 = 3x

    5x

    60 = 05x = 60

    x = 12

    2

    1 for correctexpansion

    1 for solution

    (c) i) 12-6

    = -2

    1

    ii) 3(-2 + 12)

    = 3 10

    = 30

    1

    iii) 32

    (-2)2

    12

    =9 412

    = 3

    1

    (d) i) $25 from graph 1

    ii) before 2100 (9:00pm) 1

    iii) 5.5 hours would cost $20. Two lots of under 3

    hours costs $12. The exercise would save $8.

    1

    /10

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    Question 22 Final Preliminary Examination General Mathematics

    2012

    Part Solution Marks Comment

    (a) i) $63 920 1

    ii) $3572 + 32.5% of (63 92037 000) = $12 321 1

    iii) 1.5% of $63920 = $958.80 1

    iv) $550 26 = $14300.14 300-12 321-958.80= $1020.20 refund.

    1

    (b) i) = P(1 + r)n

    = 5000(1.055)5

    = $6534.80

    1

    ii) = P(1 + r)n

    = 5000(1.0135)20

    = $6538.00

    6538-6534.80= $3.20 better off with new bank.

    2 1 for compoundinterest result.

    1 for difference.

    (c)i) 45.6

    35 + 68.4

    5 + 91.2

    3 = $2211.60

    2 1 for correctvalues forovertime/effectivehours worked.

    1 for result.

    ii) 24% of $2211.60 = $530.78 (tax)

    2211.6 530.78 = $1680.82 net pay

    1

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    Question 23 Final Preliminary Examination General Mathematics

    2012

    Part Solution Marks Comment

    (a) cosA = 6.511.3

    A = 5453

    A = 55

    1

    (b) 2 = 62

    + 92

    2= 117

    x= 10.8cm

    2 1 for lengthof 9 cm

    1 for correctanswer.

    (c) (i) 1

    (ii) tan 56=79x

    x= 79

    tan 56

    x= 53.286

    x= 53.3m

    2 1 for correctratio

    1 for correctanswer

    79m

    56o

    x

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    Question 23 Final Preliminary Examination General Mathematics

    2012

    Part Solution Marks Comment

    (d)

    B BBBB

    G BBGB

    B BGBG

    G BGG

    B GBB

    BG GBG

    GB GGB

    GG GGG

    2 1 for any

    method usedto find thesample space

    1 for correctlist ofoutcomes.

    (e) i) P(spanner away from car) = P(spanner under car)

    = 1

    0.85

    = 0.15

    1

    ii) 60 0.85 = 51 1

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    Question 24 Final Preliminary Examination General Mathematics

    2012

    Part Solution Marks Comment

    (a) i) 130 cm 1

    ii) 134.25cm134.75cm 1

    iii) 0.25 134.5 = 0.186% 1

    (b) i) 100 11 = 9.09 km/L 1

    ii) 65 9.09 = 590.85 (591 km to nearest km) 1

    (c) i) V= r2h

    = 22

    2.5

    = 31.415. . .

    31 m3

    1

    ii) 31000 300 = 103..

    3

    so 103 hours 20 mins are needed to fill the tank.

    1 Accepteither.

    iii)

    SA = 2r(r+h)

    = 2 2(2 + 2.5)

    = 18

    = 56.55

    57 m2

    2 1 for correctsubstitution

    1 for correctanswer

    iv) 57 240 = $ 13 680

    Also accept $13 571.68 using 18

    1

    /10

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    Question 25 Final Preliminary Examination General Mathematics

    2012

    Part Solution Marks Comment

    (a) 620

    are tagged, or 30%

    30% = 1510% = 5100%= 50

    2 1 mark for correctpercentage/decimalor alternate method1 for solution

    (b) i)3 7 8 94 2 3 6 7 8 95 0 2 2 2 3 3 5 76 1 3 5

    1

    ii) range = 65 37 = 28

    median = 51Q1 = 44.5Q3= 54

    interquartilerange = 54 44.5 = 9.5

    2 1 for each response

    iii) 37, 44.5, 51, 54, 65

    37 44.5 51 54 65

    2 1 for summary,

    1 for plot

    Plot should haveappropriate scale

    iv) x = 50.1 sample standard deviation = 7.9 2 1 for each response

    (c) median as it is less affected by outliers. 1/10