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COMMONWEALTH SECONDARY SCHOOL PRELIMINARY EXAMINATION 2009 SECONDARY FOUR EXPRESS/FIVE NORMAL MATHEMATICS 4016/02 1

(i)

Amt. of money paid = $1.870 × 42 = $78.54 50 1.870 ≈ 26.73797 litres Dist. = 26.73797 × 12.5 ≈ 334 km

(ii)

Amt. of petrol=

Let the max. volume be V litres. 1.687V − 5 < 0.85 × 1.767V 1.687V − 5 < 1.50195V 0.18505V < 5 V < 27.0197 Max. volume is 27.0 litres.

(iii)

(i)

Elegant handbags : Convenient handbags = 7500 : 7260 = 125 : 121 0.15 × 7500 + 50 × 100% 7500 + 7260 ≈ 7.96%

% discount =

(ii)

2

(a) ●

[B1]

[M1] [A1] [M1]

[A1] [A1]

[B1] [M1] [A1] [B1]















































● ● ● ●

● ●



(b)





p = 33 q = 46

[B1] [B1]

2 (c)

2 = n + 2 ( n − 1) = n 2 + 2n − 2

no. of dots A =1 B=2 C = −2

3

[B1] [B1] [B1]

2 = 10 + 2 ( 10 ) − 2 = 118

(d)

no. of dots

(e)

n 2 + 2n − 2 = 253 n 2 + 2n − 255 = 0 ( n − 15 ) ( n + 17 ) = 0 n = 15 or n = −17 (N.A) Diagram 15 has 253 dots. (other methods are acceptable)

(a)

[B1]

a 2 − 6ab + 9b2 5a2 − 45b2 ÷ 6ac − 3ad 2ac − ad + 6bc − 3bd 2 ( a − 3b ) × a ( 2c − d ) + 3b ( 2c − d ) = 3a ( 2c − d ) 5 ( a + 3 b ) ( a − 3b )

(i)

[M1]

[A1]

[M1]

( a − 3b ) × ( 2c − d ) ( a + 3b ) = 3a ( 2c − d ) 5 ( a + 3b ) ( a − 3b ) 2

=

[M1]

a − 3b 15a

[A1]

3 5 −4= 2 ( x − 1) 3 ( x − 1)

(ii)

9 − 24 ( x − 1) = 10

[M1]

24 ( x − 1) = −1 x −1= − x=

(b)

4

1 24

23 24

[A1]

(i)

P(choosing a green disc) = 1 − p

(ii)

(a)

P(red disc chosen each time)

(b)

P(at least one green disc chosen) = 1 – P(red disc chosen each time) = 1 − p8

[B1] = p8

[B1]

[B1]

By Sine Rule, [M1]

CSS/Prelim2009/MATH/SEC4E5N/P2/AGS/Page 2 of 6

3 sin ∠CBE sin35° = 7.3 4.6 ∠CBE = 180° − 65.538659° ≈ 114.46134° ≈ 114.5°

[A1]

CA 4.6 CA ≈ 5.6805269 ≈ 5.68 cm

tan51° =

[B1]

By Cosine Rule, AD 2 = 5.68052692 + 42 − 2 ( 5.6805269 ) (4)cos103°

[M2]

AD ≈ 7.647948 ≈ 7.65 cm

[A1]

∠BCE = 180° − 35° − 114.46134° (∠s sum of ∆ ) = 30.53866° 1 Area of ∆BCE = ( 4.6 ) ( 7.3 ) sin30.53866° 2 ≈ 8.5313285 ≈ 8.53 cm2

[A1]

1 × 4.6 × shortest dist. = 8.5313285 2 Shortest dist. ≈ 3.70927 ≈ 3.71 cm 5

(a)

(b) (c)

[M1] [A1]

90 × 600 100 = 540 km/h  3500  Time taken (with wind) = h  540 + x 

Speed of plane

[M1]

=

 3500  Time taken (against wind) =  h  540 − x  3500 3500 10 − =1 540 − x 540 + x 60 3000 3000 − =1 540 − x 540 + x 3000 ( 540 + x ) − 3000 ( 540 − x ) = ( 540 + x ) ( 540 − x ) 1620000 + 3000 x − 1620000 + 3000 x = 291600 − x 2 x 2 + 6000 x − 291600 = 0 (Shown)

[B1]

[B1] [M1]

[M1] [A1]

CSS/Prelim2009/MATH/SEC4E5N/P2/AGS/Page 3 of 6

4

(d)

x 2 + 6000 x − 291600 = 0 x=

−6000 ± 60002 − 4 ( 1) ( −291600 )

2 ( 1) ≈ 48.21259 or −6048.212 (N.A.) ≈ 48.2

(e)

6

(a)

Time taken

(i)

(ii)

(iii)

(b)

7

(a)

[A1] [A1] [M1]

3500 600 + 48.21259 ≈ 5.399 h ≈ 5 h 24 min

=

[A1]

∠TOP = 36° × 2 (∠ at ctr. = 2 × ∠ at circumference) = 72° Reflex ∠POT = 360° − 72° (∠s at a pt.) = 288°

[M1]

∠TSP = 180° − 36° (opp. ∠s of cyclic quad.) = 144° 180° − 144° ∠PTS = (base ∠ of isos. ∆ ) 2 = 18°

[M1]

∠PTR = 90° (∠ in a semicircle) ∠QTS = 180° − 90° − 18° (∠s on a st. line) = 72° ∠SQT = 180° − 2 ( 72° ) (∠s sum of isos. ∆ ) = 36° ∠QPR = 90° (tangent ⊥ rad.) ∠PQR = 180° − 90° − 36° (∠s sum of ∆ ) = 54° ∠PQS = 54° − 36° = 18°

∠SPT = 18° (isos. ∆ ) 180° − 72° ∠TPO = (base ∠ of isos. ∆ ) 2 = 54° ∠QPS = 90° − 54° − 18° = 18° ∠ Since QPS = ∠SPT = 18° , PS bisects ∠QPT . (i)

[M1]

62 × 2π ( 1.8 ) 360 ≈ 1.947787

dist. moved =

[A1]

[A1]

[M1] [M1] [A1] [M1] [M1] [A1] [M1] [A1]

CSS/Prelim2009/MATH/SEC4E5N/P2/AGS/Page 4 of 6

5 ≈ 1.95 m (ii)

(b)

(i)

(ii) 8

(i)

No. of oscillations in 1 min = 2.5 Dist. travelled in 1 min = 2.5 × 1.95 × 2 ≈ 9.7389 ≈ 9.74 m Speed is 9.74 m/min. Let the angle of depression be a° . 1.8 tan a° = 4 a ≈ 24.2277 ≈ 24.2 Angle of depression is 24.2° . dist.2 = 42 + 1.82 (by Pythagoras' Thm.) dist. ≈ 4.39 m

Vol. of hemisphere =

1 4 3 × ( π ) ( 7) 2 3 ≈ 718.3775201 ≈ 718 cm3

(ii) Let the base radius of the cone be r cm . 1 2 ( π ) ( r ) ( 10 ) × 3 = 718.3775201 3 Base radius of cone is 4.78 cm. (iii)

(iv)

r ≈ 4.781910357 ≈ 4.78

(b)

[A1]

[M1] [A1] [M1] [A1] [M1] [A1]

[M1] [A1]

1 Mass = 0.9 × × 718.3775201 3 ≈ 215.5132 ≈ 216 g Let the slanted height of the cone be l cm . l 2 = 102 + 4.78192 (by Pythagoras' Thm.) l ≈ 11.0845 Total external surface area 2 2 = 3π ( 7 ) + π ( 4.7819 ) ( 11.0845 ) + π ( 4.7819 ) ≈ 700.171587 ≈ 700 cm2

1 2 ( 6 ) θ = 98 2 4 θ = 5 rad. 9

[M1]

[M1] [A1]

[M1] [M2] [A1]

[M1]

CSS/Prelim2009/MATH/SEC4E5N/P2/AGS/Page 5 of 6

6

9

 4 Perimeter of major sector = 6  5  + 2 ( 6 )  9 2 = 44 cm 3

[A1]

(a)

Median daily wage ≈ $43

[B1]

(b)

Interquartile range ≈ $49 – $36 = $13

[M1] [A1]

(c)

77.5% of the male employees

22.5 × 80 100 = 18 =

z ≈ 35

[M1] [A1]

(d)

Median daily wage ≈ $38 Interquartile range ≈ $46 – $18 = $28

[B1] [M1] [A1]

(e)

The median wage of males ($43) is higher than that of females ($38). The interquartile range for wage of males (13) is smaller than that of females (28) and thus, the wage of males is less widespread as compared to that of females.

[B1]

(f)

26 + 30 140 2 = 5

P(wage less than or equal to $38) =

[B1]

[M1] [A1]

CSS/Prelim2009/MATH/SEC4E5N/P2/AGS/Page 6 of 6

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