# 2016 April(72E) Math Question 1

**Choice D**

$$\frac{x}{72}=\frac{1\frac{3}{4}}{24} \\$$
$$ \Rightarrow x=5\frac{1}{4}$$

# 2015 December(72E) Math Question 2

**Choice H**

$$\frac{57+61+57+57+58+57}{6}=57.8$$

# 2015 December(72E) Math Question 3

**Choice A**

$$120=1.8K-459.67 \\$$
$$ \Rightarrow K\approx 322$$

# 2015 December(72E) Math Question 4

**Choice F**

$$-\frac{18}{3}x^{3-1}y^{2-1}=-6x^2y$$

# 2015 December(72E) Math Question 5

**Choice C**

$$\sqrt{a}=9 \Rightarrow a=81$$

# 2015 December(72E) Math Question 6

**Choice G**

$$\frac{80\times15\%}{5}=2.4$$

# 2015 December(72E) Math Question 7

**Choice B**

$$0.000000000087=8.73\times 10^{-11}$$

# 2015 December(72E) Math Question 8

**Choice J**

$$\frac{360}{6}=60$$

# 2015 December(72E) Math Question 9

**Choice E**

$$\frac{4+45}{9}=\frac{49}{9}$$

# 2015 December(72E) Math Question 10

**Choice G**

$$\begin{bmatrix}2\times1+3\times2 & 2\times2+3\times1 \\2\times3-3\times1 & 2\times4-3\times2 \end{bmatrix}=\begin{bmatrix}8 & 7 \\3 & 2 \end{bmatrix}$$

# 2015 December(72E) Math Question 11

**Choice D**

The speed of one motorcycle exceeds 4 times the speed of another motor cycle by 24 mph:
4g+24

# 2015 December(72E) Math Question 12

**Choice J**

$$Area=\frac{12\times8}{2}=48$$

# 2015 December(72E) Math Question 13

**Choice C**

Only the equation in C fulfils all data sets in the table.

# 2015 December(72E) Math Question 14

**Choice H**

$$Driving \ time = \frac{1200}{50}=24 \\$$
$$ Unloading \ time = 12 \\$$
$$ \Rightarrow Total \ time=24+12+30=66=24+24+18$$

# 2015 December(72E) Math Question 15

**Choice C**

$$x+5y=3 \Rightarrow x=-5y+3$$

# 2015 December(72E) Math Question 16

**Choice H**

Thus the other side is also 16; the remaining 2 sides are:
$$\frac{80-16-16}{2}=24$$

# 2015 December(72E) Math Question 17

**Choice D**

$$6l+4s=26 \\$$
$$ 2l+4x=14 \\$$
$$ \Rightarrow l=3$$

# 2015 December(72E) Math Question 18

**Choice K**

$$2\times6\times5=60$$

# 2015 December(72E) Math Question 19

**Choice C**

$$26+2\times5+1.5\times \frac{12}{3}=42$$

# 2015 December(72E) Math Question 20

# 2015 December(72E) Math Question 21

**Choice E**

$$200x=500+20\times30 \\$$
$$ \Rightarrow …

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# 2015 December(72E) Math Question 22

**Choice K**

$$\frac{9}{10+5+10+9+9+7}=18\%$$

# 2015 December(72E) Math Question 23

**Choice B**

The length of the rectangle is w + 12; the area is $$w\cdot l=140 \\$$
$$ \Rightarrow w\cdot (w+12)=140$$

# 2015 December(72E) Math Question 24

**Choice H**

$$\sqrt{(-8-4)^2+(4-9)^2 …

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# 2015 December(72E) Math Question 25

**Choice E**

(6,3+(7-3)+(7-3))=(6 …

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# 2015 December(72E) Math Question 26

**Choice H**

$$Area = \pi r^2=\pi …

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# 2015 December(72E) Math Question 27

**Choice D**

$$\frac{99+98+88\times …

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# 2015 December(72E) Math Question 28

**Choice J**

Among the choices, only 60 …

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# 2015 December(72E) Math Question 29

**Choice A**

$$x^2-x-72=(x-9)(x+8)$$

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# 2015 December(72E) Math Question 30

**Choice F**

$$Volume=\pi r^2 h …

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# 2015 December(72E) Math Question 31

**Choice E**

$$\sin C= \frac{AB}{AC …

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# 2015 December(72E) Math Question 32

**Choice H**

$$\angle R= \angle P=54 …

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# 2015 December(72E) Math Question 33

**Choice B**

g(1) > 0

g(2 …

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# 2015 December(72E) Math Question 34

**Choice J**

$$b=3n \\$$
$$\Rightarrow \frac{1 …

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# 2015 December(72E) Math Question 35

**Choice E**

$$g=b+15 \\$$
$$ r=g …

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# 2015 December(72E) Math Question 36

**Choice K**

$$(5-2)\times 180°-70°-100 …

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# 2015 December(72E) Math Question 37

**Choice A**

$$WD=\frac{6}{2}=3 …

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# 2015 December(72E) Math Question 38

**Choice G**

OS=2r

Thus S(0 …

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# 2015 December(72E) Math Question 39

**Choice B**

‘x varies directly with y …

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# 2015 December(72E) Math Question 40

**Choice G**

$$(|x|-2)(|x|+1)=0 …

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# 2015 December(72E) Math Question 41

**Choice B**

The line ST is going …

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# 2015 December(72E) Math Question 42

**Choice H**

$$(\frac{1+4}{2},\frac …

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# 2015 December(72E) Math Question 43

**Choice D**

$$\tan \angle STR = \frac{SR …

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# 2015 December(72E) Math Question 44

**Choice F**

SR is the radius which …

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# 2015 December(72E) Math Question 45

**Choice D**

A cube has 6 sides …

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# 2015 December(72E) Math Question 46

**Choice K**

y=-3-5=-8

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# 2015 December(72E) Math Question 47

**Choice B**

$$y=\frac{4}{3}x …

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# 2015 December(72E) Math Question 48

**Choice K**

K: |x|=x

When x …

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# 2015 December(72E) Math Question 49

**Choice A**

$$Area = \frac{AB+CD}{2 …

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# 2015 December(72E) Math Question 50

**Choice J**

$$x^2={\sqrt{a}}^2 …

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# 2015 December(72E) Math Question 51

**Choice A**

$$\tan\alpha=\frac{50-5}{80 …

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# 2015 December(72E) Math Question 52

**Choice G**

Firstly, one need to identify …

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# 2015 December(72E) Math Question 53

**Choice A**

$$\frac{3}{6}\cdot\frac …

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# 2015 December(72E) Math Question 54

**Choice H**

$$Area = (18-2x)(12-x)=2x^2-42x_216$$

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# 2015 December(72E) Math Question 55

**Choice B**

The graph is reflected over …

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# 2015 December(72E) Math Question 56

**Choice K**

$$\frac{x^{24}}{x^6 …

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# 2015 December(72E) Math Question 57

**Choice A**

$$a\cdot b=-48 \\$$
$$ a …

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# 2015 December(72E) Math Question 58

**Choice K**

$$Area = 6\times(4+6 …

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# 2015 December(72E) Math Question 59

**Choice A**

$$\frac{6}{7}\times \frac …

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# 2015 December(72E) Math Question 60

**Choice G**

$$(x+3)^2=x^2 …

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