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

# 2017 December(A10) Math Question 9 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

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

# 2017 December(A10) Math Question 19 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

# 2017 December(A10) Math Question 26 Choice F

# 2017 December(A10) Math Question 28 Choice H 8+6+12+8+6 …

# 2017 December(A10) Math Question 29 Choice A

# 2017 December(A10) Math Question 31 Choice C

# 2017 December(A10) Math Question 33 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 …

# 2017 December(A10) Math Question 36 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

# 2017 December(A10) Math Question 42 Choice G

There is only one correct …

# 2017 December(A10) Math Question 43 Choice D

# 2017 December(A10) Math Question 47 Choice D

# 2017 December(A10) Math Question 50 Choice K

# 2017 December(A10) Math Question 53 Choice E

# 2017 December(A10) Math Question 55 Choice B

Since x, y and z …

# 2017 December(A10) Math Question 56 Choice G

# 2017 December(A10) Math Question 58 Choice J # 2017 December(A10) Math Question 60 Choice K 