# 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 Choice K

180-34=146

# 2015 December(72E) Math Question 21 Choice E

# 2015 December(72E) Math Question 25 Choice E

(6,3+(7-3)+(7-3))=(6 …

# 2015 December(72E) Math Question 26 Choice H

# 2015 December(72E) Math Question 28 Choice J

Among the choices, only 60 …

# 2015 December(72E) Math Question 29 Choice A

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

# 2015 December(72E) Math Question 30 Choice F

# 2015 December(72E) Math Question 32 Choice H

# 2015 December(72E) Math Question 35 Choice E

# 2015 December(72E) Math Question 37 Choice A

# 2015 December(72E) Math Question 41 Choice B

The line ST is going …

# 2015 December(72E) Math Question 42 Choice H

# 2015 December(72E) Math Question 44 Choice F

SR is the radius which …

# 2015 December(72E) Math Question 45 Choice D

A cube has 6 sides …

# 2015 December(72E) Math Question 46 Choice K

y=-3-5=-8

# 2015 December(72E) Math Question 47 Choice B

# 2015 December(72E) Math Question 50 Choice J

# 2015 December(72E) Math Question 52 Choice G

Firstly, one need to identify …

# 2015 December(72E) Math Question 53 Choice A

# 2015 December(72E) Math Question 57 Choice A

# 2015 December(72E) Math Question 59 Choice A