# 2017 December(A10) Math Question 1

Choice B

$$p=\frac{5}{19}+\frac{4}{19}=\frac{9}{19}$$

# 2017 December(A10) Math Question 2

Choice G

$$p=\frac{2}{8+12+6+2}=\frac{2}{28}=\frac{1}{14}$$

# 2017 December(A10) Math Question 3

Choice A

$$k=\frac{7}{5}j+54=40\Rightarrow j=-10$$

# 2017 December(A10) Math Question 4

Choice H

$$|3-x|=|3-8|=|-5|=5$$

# 2017 December(A10) Math Question 5

Choice A

Let d be the change in temperature: $$24+d=-16\Rightarrow d=-40$$

# 2017 December(A10) Math Question 6

Choice G

$$1000+200\times 28-5400=1200$$

# 2017 December(A10) Math Question 7

Choice E

It can be proved that each side equals to 4. $$perimeter=4\times 6=24$$

# 2017 December(A10) Math Question 8

Choice J

$$S_1=22\times40=880\\$$ $$S_2=22\times28=616\\$$ $$\Rightarrow S_1+S_2=1496$$

Choice C

# 2017 December(A10) Math Question 10

Choice H

$$g(4)=\frac{4^2}{2}=\frac{16}{2}=8\\$$$$\Rightarrow f(g(4))=f(8)=3\times 8+7=31$$

# 2017 December(A10) Math Question 11

Choice E

$$profit=sales \ revenue-cost \ of \ sales=2h-200>0$$

# 2017 December(A10) Math Question 12

Choice G

$$3x+8y=5$$ $$\Rightarrow 8y=-3x+5$$ $$\Rightarrow y=-\frac{3}{8}x+\frac{5}{8}$$

# 2017 December(A10) Math Question 13

Choice A

$$x+2y=2\ (given)\Rightarrow x=2-2y \ (a)\\$$ $$-2x+y=16 \ (given) \ and \ (a) \Rightarrow -2(2-2y)+y=16\Rightarrow y=4 \\$$ $$\Rightarrow x= 2-2\times4=-6$$

# 2017 December(A10) Math Question 14

Choice K

$$\frac{x \ miles}{2\frac{3}{4}inches}=\frac{16\ miles}{\frac{1}{4}\ inches}\\$$ $$\Rightarrow \frac{x}{\frac{11}{4}}=\frac{16}{\frac{1}{4}}\\$$ $$\Rightarrow \frac{x}{11}=\frac{16}{1}\\$$ $$\Rightarrow x=16\times11=176 \ miles$$

# 2017 December(A10) Math Question 15

Choice E

$$4\begin{bmatrix}-1&2\\0&-4\\ \end{bmatrix}=\begin{bmatrix}-1\times4&2\times4\\0\times4&-4\times4\\ \end{bmatrix}=\begin{bmatrix}-4&8\\0&-16\\ \end{bmatrix}$$

# 2017 December(A10) Math Question 16

Choice J

$$tan \ A=\frac{15}{8}$$

# 2017 December(A10) Math Question 17

Choice D

$$x=\frac{8 \ miles}{60 \ minutes}\times12 \ minutes=1\frac{3}{5}$$

# 2017 December(A10) Math Question 18

Choice G

$$f(-3)=-6\cdot(-3)^2=-6\cdot9=-54$$

Choice B

# 2017 December(A10) Math Question 20

Choice F

$$Let \ the \ linear \ function \ be \ y=kx+b \\$$ $$\Rightarrow 2=5k+b\\$$ $$6=15k+b\\$$ $$\Rightarrow k=\frac{2}{5},\ b=0\\$$ $$y=\frac{2}{5}x$$

# 2017 December(A10) Math Question 21

Choice C

When at noon (12pm), the …

# 2017 December(A10) Math Question 22

Choice K

Let the points on the …

# 2017 December(A10) Math Question 23

Choice A

The area of 10 pins …

# 2017 December(A10) Math Question 24

Choice G

$$\frac{65\times3\frac{1}{2}}{5\times3\frac{1}{2}}=\frac{13}{1}$$

Choice D

Choice H

8+6+12+8+6+12=52

# 2017 December(A10) Math Question 29

Choice A

$$2500\times \frac{4}{10}\times \frac{3}{8}=375$$

Choice H

# 2017 December(A10) Math Question 32

Choice J

$$BD=\sqrt{BC^2-CD^2}=\sqrt{13000^2-12000^2}=5000\\$$ $$\Rightarrow AB=AD+DB=9000+5000=14000$$

Choice C

# 2017 December(A10) Math Question 34

Choice G

$$t=\frac{9000}{300}=30$$

# 2017 December(A10) Math Question 35

Choice A

B is apparently decreasing. C …

Choice G

# 2017 December(A10) Math Question 38

Choice J

Let L be the length …

# 2017 December(A10) Math Question 39

Choice C

The range and the mean …

# 2017 December(A10) Math Question 40

Choice K

Ruben completed $$1-\frac{2}{5}-\frac{1}{3}=\frac{4}{15}$$ The total …

# 2017 December(A10) Math Question 41

Choice C

$$\frac{(2a^{-1}\sqrt{b})^4}{ab^{-3}}=\frac{2^4a^{-4}(\sqrt{b})^4}{ab^{-3}}=\frac{16b^2}{a^5b^{-3}}=\frac{16b^5}{a^5}$$

# 2017 December(A10) Math Question 42

Choice G

There is only one correct …

# 2017 December(A10) Math Question 43

Choice D

$$\frac{\frac{x}{3}+\frac{1}{2}}{\frac{2}{3}-\frac{1}{4}}=\frac{\frac{2x+3}{6}}{\frac{8-3}{12}}=\frac{\frac{2x+3}{6}}{\frac{5}{12}}=\frac{2x+3}{6}\cdot \frac{12}{5}=\frac{(2x+3)\cdot2}{5}=\frac{4x+6}{5}$$

# 2017 December(A10) Math Question 44

Choice K

10×10×10×26×26×26=17576000

# 2017 December(A10) Math Question 45

Choice A

The function is moved to …

# 2017 December(A10) Math Question 46

Choice K

$$x=5^{-2}=\frac{1}{25}$$

# 2017 December(A10) Math Question 47

Choice D

$$\frac{1}{5}=\frac{2}{10} \\$$ $$\frac{1}{3}=\frac{2}{6}$$ The …

# 2017 December(A10) Math Question 48

Choice F

The effect of a number …

Choice B

# 2017 December(A10) Math Question 51

Choice D

As seen from the diagram, …

Choice J

Choice J

# 2017 December(A10) Math Question 58

Choice J

$$(x-7)^2+(y-8)^2=10 \\$$ $$y=11 \\$$ …

# 2017 December(A10) Math Question 59

Choice D

$$V_0=30\times25\times5\\$$  V_1=30\times 110\%\times 25\times110\%\times5=(110\%)^2\times30\times25\times5=(110\%)^2\times …

Choice K