**Choice E**

Draw the blue one twice, …

**Choice J**

$$3\ pieces=x,\ y,\ z$$ $$x=2y=2(2z)=4z$$ $$y=2z$$ $$\Rightarrow x+y+z=4z+2z+z=21$$ $$\Rightarrow 7z=21$$ $$\Rightarrow z=3$$ $$x=4z=12$$

**Choice C**

$$(8+3)2=22$$

**Choice C**

$$\triangle BCD is a 6-8-10 triangle.$$ $$\overline{BD}=10$$ $$\underline{AB}=\overline{BD}=\overline{AD}=10$$

**Choice D**

$$\Rightarrow\frac{S+T}{2}$$ $$=\frac{(4,10)+(6,-2)}{2}$$ $$=\frac{(10,8)}{2}$$ $$=(5,4)$$

**Choice C**

$$\frac{1}{a}=2$$ $$\frac{1}{b}=3$$ $$\frac{1}{2}(\frac{1}{a}+\frac{1}{b})$$ $$=\frac{1}{2}(2+3)$$ $$=\frac{5}{2}$$

**Choice C**

$$20\ mins=\frac{1}{3}\ hr$$ $$50\times\frac{1}{3}=16.666\approx17$$

**Choice H**

$$$1=100¢$$ $$0.40\times x+0.25\times(20-x)=6.95$$ $$0.4x+5-0.25x=6.95$$ $$0.15x=1.95$$ …

**Choice B**

$$3x-2y=6$$ $$-2y=6-3x$$ $$2y=3x-6$$ $$y=\frac{3}{2}x-3$$ $$y=mx+b$$ …

**Choice G**

$$\sin 6°=0.1045=\frac{?}{4}$$ $$?=0.1045\times4=0.418$$

**Choice E**

$$Level\ 1=4\times5$$ $$Level\ 2=4\times6$$ $$Level\ …

**Choice J**

$$F.\sqrt{-5^{2}}=5$$ $$G.\sqrt{-2^{2}}=2$$ $$H.\sqrt{\frac{1}{2}^{2}}=\frac{1}{2}$$ $$\frac{1}{2}\ is\ …

**Choice B**

$$16(16-6)(\frac{1}{2})=80$$

**Choice K**

$$x-y\lt0$$ $$Let\ x=1,\ y=2$$ $$F.\ …

**Choice E**

Move down two units, the …

**Choice G**

$$-6+7k \geq 3-8k$$ $$\Rightarrow 15k …

**Choice C**

$$\Rightarrow \overline{AB}=4\overline{GH}$$

**Choice F**

$$2\frac{1}{3}\times\frac{1}{2}=1\frac{1}{6}$$

**Choice B**

$$6+1\times x=3+1\frac{1}{2}x$$ $$3=\frac{1}{2}x$$ $$x=6$$

**Choice K**

$$\Rightarrow x^{3}-4x^{2}-x^{2}+5x+3x+6$$ $$\Rightarrow x^{3}-5x^{2}+8x+6$$

**Choice A**

$$\tan \theta=\frac{0.5}{1}$$ $$\Rightarrow \tan \theta=\frac{1}{2}$$ …

**Choice G**

**Choice C**

$$\pi r^{2}=16\pi $$

**Choice K**

**Choice B**

**Choice F**

**Choice D**

$$r=\frac{10}{2}=5$$ $$\pi r^{2}h=\pi 5^{2}h=1000$$ $$h=1000\div25\div\pi=\frac{40}{\pi}\approx\frac{40}{3.14}=12.73$$

**Choice J**

$$1-\frac{1}{12}\times3=\frac{9}{12}=\frac{3}{4}$$ $$\frac{3}{4}\times\frac{1}{5}=\frac{3}{20}$$

**Choice A**

$$x=\frac{-b\pm\sqrt{b^{2}-4ac}}{2a}$$ $$=\frac{-(-5)\pm\sqrt{(-5)^{2}-4(1)(3)}}{2(1)}$$ $$=\frac{5\pm\sqrt{25-4(1)(3)}}{2(1)}$$

**Choice F**

$$(9,-13)+(a,b)=2(1,-6)=(2,-12)$$ $$9+a=2\ \Rightarrow\ a=-7$$ $$-13+b=-12\ …

**Choice B**

Let the base of the …

**Choice K**

$$(0,-1)\Rightarrow G,\ K$$ $$(K). m=3,\ …

**Choice D**

$$(10+18)\times 3\times\frac{1}{2}=42$$

**Choice G**

$$C=99\times h$$ $$m=0.99$$

**Choice D**

$$4,10,25$$ $$10\div4=2.5$$ $$25\div10=2.5$$ $$25\times2.5=62.5$$

**Choice J**

$$64=x^{3}$$ $$x=4$$ $$Total\ surface\ area=4\times4\times6=96$$

**Choice C**

$$2\pi r=2 \pi(4)=8\pi$$ $$\frac{7 \pi}{8\pi}=\frac{315}{360}$$ …

**Choice K**

The equation for a circle …

**Choice D**

$$\frac{a}{\sin A}=\frac{b}{\sin B}=\frac{c}{\sin C}$$ $$\Rightarrow …

**Choice F**

$$The\ side\ of\ square1:1+l$$ $$The\ …

**Choice E**

$$If\ \ x\leq2\ , then\ …

**Choice H**

More than 6 rooms:25-10=15

6 …

**Choice B**

$$\Rightarrow (\cos x)^{2}=(-\frac{1}{3})^{2}=\frac{1}{9}$$ $$\frac{1}{9}=\frac{1+\cos 2x}{2}$$ …

**Choice F**

$$y=f(g(x))=\sqrt{10x+b}$$ $$(4,6)\Rightarrow 6=\sqrt{10\times4+b}$$ $$\Rightarrow 36=40+b$$ …

**Choice A**

**Choice F**

$$b^{2}\gt 0;$$ $$(c^{2})^{2}\gt 0;$$ $$\Rightarrow …