1980-04-26 — Page 22

華僑日報 All

買二第張六第

日二十月三年申庚麽至

WAH KIU YAT PO

郭日僑華

六期星

日六廿月四年〇八九一腊公年九十六國民餘中

1980

(x5)(5x16) K0

MC

Or

<3 or

*> 16

6x+2y

sine

(b)

AC

中學會考試題預習專欄

SECTION B

新數學 C卌D

Combine the results of the two inequality, we obtain

9(a) Let a = the first term

of the progres-

2.052

10

0.2052

sion

11 50

明德出版社魯榮家提供資料

20 < x <- 2

(Ans.)

the common

•.[CAC

20

MODERN MATHEMATICS (30)

W.K. LO

(MILL & DALE PRESS LTD.)

2y

(1)

ratio of the progression

(b) AM

AC,coso

SUGGESTED SOLUTIONS TO

243

REVISION EXERCISE, PAPER I.

10co8l1°50 9.787 m

SECTION A

47

27

8.

1. (a) A ADE CO A BEC

From (2)

a = 27(1-r)

~27(1+r) (r)

2

9r2-9r + 2 = 0

COS / DAN = 9.787

* 0.8174

ZDAM = 35°10'

the angle between AD and the plane ACC' is 35°10. (Ans.)

(c) If 60% 6 of students

passed in the test, then 20 students with scores less than the pase mark. From the graph, the pass mark is 60.

4(a) The equation of L is:

0

(Ans.)

3

347

Area of BEC

Area of ADE

(4)2-4

·(2)

From (2):

Area of BBC

2. (31 −2)(3r-1)

2

4 x (Area of A ADE)

4 x 4 cm2

16 cm

Let the area of AAEF

be X cm2 and the area

of A CFE be Y cm

3(4y-5)

or

(Ans.)

(Ans.) (Ans.)

As r is less than therefore r

3.

Substitute

15-2

245

(b) Assume

5

(3-1) (2+3).

(3+1)

13-1 (3+1)(3−1)

↑ (Ans.)

be taken

a(1–

into (1)

(Ane.)

në must

(1-1) > 26.9 18[1-(3) *] -

> 26.

271-26.9

27-27 26.9

0.1727(3

(3)<270

nlog(3) < 198270

2.4314

-0.4771n

n>

(where k is

constant)

n>5.096

terma

taken (Ans.)

10(a)

If y is increased by 10% then

(1.1y)

1-21 (2)

0.8264

it is decreased by (1-0.8264)x100%

S

X

Let E = the set of

students passed

in English

= the get of

students passed

in Chinese

the set of students passed in Mathematica

the number of

students passed all subjects Since there are altoge 60 students passed in English, therefore (10−x)+(x)+(25-x)+(30)

x = 5

(a)(1) The required

probability

60

(b) Radius of the circle

(16–3)2 + (7-3)2

The equation of the circle

18

(x-6)2+(y-7)2= 25

(Ana.)

2x + y = 14 = 0 ...(1) (x-6)2+(y~7)2 = 25....(2)

From (1):

Y = 14

Substitute (3) into

(3)

(x−6) + (14-21-7)———

(x-6)2+(7-2x)?

25

−12x+36+49~28x+4x2=25

2-40x+60=0

-8x+12 = 0 (x−6)(x-2)

X2 or

when x 2,

J = 10

when x

y 2

P and Q are (2,10) and

(6,2)

15(a)(1). CF:FD = 1:2

and BA - 153

(3)- (3) 2 = 4

(1)

,4X-57+16 = 0.

XY+16 (A) 2 (+)2=

8X-Y-16

(2) x 5:

40X-51-80.

(3) - (1)

36X-96 -

(cm2)

(Ans.)

2(a) Let the cost of A be

SP

..C paid:

20

x (1+206)

1.08P

1.08P-P = 3600

0.082 3600

P45000,

(1-100)

paid $45000 (Ans.)

B paid $45000 x

120 100

854000 (Ana.)

C paid $45000 x (1-100)

$48600 (Ans.)

(b) Profit of A

$54000 $45000

$9000

(Ans.)

B losses $54000-$48600

Multiply

$5400 (Ane.))

both sides by (x-3)2 2(x-3)2 < (x-3) 2(x-3)2-(x-3)< 0 (x-3)[2 (x-3)-1]<0 (x-3)(2x-7) <0

3<^<} ===3<5 Multiply

both sides by (x-3)2 (x-3)<5(x-3)? 5(x-3)2-(x-3) < 0 (x-3)[ 5(x-3)-1] < 0

2

17.36%

17.49%

LAOB

(Ans.)

2 L ACD = 30°

Area of sector AOB

300 x (71102)

2 cm

Area of ▲ BOC

7.(08)(00).sin LB0C 1.(10)(10).sin 1500

§. (10)(10).sin30°

25 cm2

Area of the shaded region

*(3π + 25) c¤

[(32) (3) + 25] on

50 em

(Ans.)

8. The centre of the circle:

(24 2-4)

Radius of the circle.

= (3-2)2+(-1-2)2

√10

the circle is.

(x-3)2+(y+1) 2 (x-3)2+(y+1)2 10

(10)?

(Ans.)

(b) From the graph, they

at 1127 (p.p.) 3 mest miles from A.

11(a)

In the figure, M is the mid-point of co'.

and

... DM_LCO

AC

CDM -

CDC!

CA in 200

2052

AB +BO

20

(Ans.)

(11) The required.

probality.

20+

(Ans.)

(111) The required

probability

150-[(60)+20+(15-x)+40]

1505130

(Ans.)

(b) The required probab-

1lity

- 30 - € (Ans.)

13(a) The mean acore

x25 + 3x35 + 5x45 +

10x55 + 14x65 + 10x75

4x85 + 2x95

62.5

(Ane,)

53 -103

101 + 5) (Ans.)

DE

AF » AD

101 -10) (Ans.) Since EM:MF = 3:2 apply the formula P

AM

2A3 + A

2(−15,5)+3(103−101)

123 (Ane.)

(11)

AM JE

12

13.42 (Ans.)

BF -√102 + 52

(111) AM.BR

11.18 (Ans.)

(61-12)) (101+53)

☐ 60-60

AML BE

(b) If BE: BC then

900

• K(101-15))+(-15.)

- ( 20 ) - 157

*

AE L BE A.

0

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