F.1 math (MC choic)

1) B
ans:
6:x=3/2:5/4
6/x = 1.5/1.25
x = 5

2) C
ans:
a:b:=4:7,a:c=3:5
a:b:=12:21,a:c=12:20
a: b: c: = 12:21:20

3) B
ans:
15:7:x=y:21:9
45:21:3x = y: 21: 9
x= 3, y = 45

4) A
ans:
AUD $1=HK$4.5
AUD $1 X 16 = HK$4.5 X 16
AUD $ 16 = HK$72

5) A
ans:
boys: girls is 3:5, 那總和就是8 份人.
全班有40 人所以男生的數目是40 x 3/8
= 15 個男生

6) C
ans:
The height and base of a triangle are in the ratio 1:2
the height of the triangle is 6cm
高是 6 cm, 底是高的2 倍, 所以底是12 cm

三角形面積: 底x 高 / 2

= 12 x 6 / 2

= 36 cm2

1)b 2)c 3)b 4)a 5)a 6)c

1. B
2. C
3. B
4. A
5. A
6. C