# 2018 April(A09) Math Question 1 Choice A

$$slope = \frac{3-(-6)}{5-(-2)}>0$$

# 2018 April(A09) Math Question 2 Choice J

(3 - 4i) + (5 + 3i) = 8 - I

# 2018 April(A09) Math Question 3 Choice C

$$\frac{630}{x}=\frac{2}{7}$$ $$x=\frac{630\times7}{2}=2205$$

# 2018 April(A09) Math Question 4 Choice K x = 40 + (180-150) = 70

# 2018 April(A09) Math Question 5 Choice C $$p=\frac{4\times4}{6\times13}\approx 0.21$$

# 2018 April(A09) Math Question 6 Choice H

$$9x-y-5=0 \\$$ $$\Rightarrow 9x-5=y \\$$ $$\Rightarrow y=9x-5$$

# 2018 April(A09) Math Question 7 Choice A

$$XY=5k\\$$ $$YZ=9k \\$$ $$\Rightarrow XZ=14k\\$$ $$\Rightarrow \frac{XY}{XZ}=\frac{5k}{9k}=\frac{5}{9}$$

# 2018 April(A09) Math Question 8 Choice G

$$2x+4\geq -8 \\$$ $$\Rightarrow 2x\geq -8-4 \\$$ $$\Rightarrow x\geq \frac{-8-4}{2}\\$$ $$\Rightarrow x\geq -6$$

# 2018 April(A09) Math Question 9 Choice E

$$(a^3)^{21}=a^{3\times21}=a^{63}$$

# 2018 April(A09) Math Question 10 Choice G

$$f(-3)=3(-3)^2+7(-3)-8=-2$$

# 2018 April(A09) Math Question 11 Choice D

$$2a+(a+3)=93\\$$ $$a=30\\$$ $$a+3=33$$

# 2018 April(A09) Math Question 12 Choice G

$$a_1=10 \\$$ $$d=2 \\$$ $$a_n=10+2(n-1)=2n+8 \\$$ $$S_n=\frac {a_1+a_n}{2}\cdot n=\frac {10+2n+8}{2}\cdot n=220 \\$$ $$n=11$$

# 2018 April(A09) Math Question 13 Choice B

$$\frac {9+x}{2}=3 \\$$ $$\frac {-11+y}{2}=-7 \\$$ $$\Rightarrow x=-3 ,\ y=-3$$

# 2018 April(A09) Math Question 14 Choice J

$$t+v=200\\$$ $$10t+6v=1400\\$$ $$\Rightarrow t=50,\ v=150$$

# 2018 April(A09) Math Question 15 Choice E

$$10\% \times 1800+200=380$$

# 2018 April(A09) Math Question 16 Choice K

$$median=250 \\$$ $$mean=\frac {200+250+300+150+275}{5}=235 \\$$ $$\Rightarrow median - mean = 250-235=15$$

# 2018 April(A09) Math Question 17 Choice E

$$Area = \frac{10\times24}{2}=120 \ dm^2$$

# 2018 April(A09) Math Question 18 Choice J

$$Mean = \frac{82+93+68+93+70+x}{7}=85 \\$$ $$\Rightarrow x=91$$

# 2018 April(A09) Math Question 19 Choice A

$$\sin A = \frac{7}{25}$$

# 2018 April(A09) Math Question 20 Choice G The longer length of the smaller rectangle (S2) = 12-5=7

$$Total\ area = S1+S2=10 \times 5 + 3 \times 7=71$$

# 2018 April(A09) Math Question 21 Choice A

x+(x+3)+(x+5 …

# 2018 April(A09) Math Question 22 Choice J

# 2018 April(A09) Math Question 25 Choice C

# 2018 April(A09) Math Question 27 Choice C

Monday:

The daily amount for …

# 2018 April(A09) Math Question 28 Choice H

To find the roots of …

# 2018 April(A09) Math Question 29 Choice D # 2018 April(A09) Math Question 32 Choice H

# 2018 April(A09) Math Question 34 Choice F

F. is apparently true, because …

# 2018 April(A09) Math Question 35 Choice B

Total distance travelled in 1 …

# 2018 April(A09) Math Question 36 Choice G

# 2018 April(A09) Math Question 38 Choice J

# 2018 April(A09) Math Question 43 Choice C

# 2018 April(A09) Math Question 50 Choice H

# 2018 April(A09) Math Question 53 Choice B # 2018 April(A09) Math Question 55 Choice E # 2018 April(A09) Math Question 58 Choice F

# 2018 April(A09) Math Question 60 Choice K