# 2013 April(71G) Math Question 1

Choice C

$$40\times12.5+6\times12.5\times2$$ $$=500+150$$ $$=650$$

# 2013 April(71G) Math Question 2

Choice K

$$\frac{4(x-6)}{3}=16$$ $$\Rightarrow 4(x-6)=16\times3=48$$ $$\Rightarrow 4x-24=48$$ $$\Rightarrow 4x=72$$ $$\Rightarrow x=18$$

# 2013 April(71G) Math Question 3

Choice A

$$2x+8=30$$ $$x=11$$

# 2013 April(71G) Math Question 4

Choice J

$$\Rightarrow 6x-3=3x+1$$ $$\Rightarrow 3x=4$$ $$\Rightarrow x=\frac{4}{3}$$

Choice A

# 2013 April(71G) Math Question 6

Choice K

$$5\times6\times5=150$$

# 2013 April(71G) Math Question 7

Choice E

$$120-(-29)=149$$

# 2013 April(71G) Math Question 8

Choice G

$$=\frac{3\times4+1\times5}{3\times1-4\times5}$$ $$=\frac{12+5}{3-20}$$ $$=\frac{17}{-17}$$ $$=-1$$

# 2013 April(71G) Math Question 9

Choice E

$$x=3,y=0\Rightarrow (3,0)$$ $$x=0,y=6\Rightarrow (0,6)$$ $$(3,0+4)=(3,4)$$ $$(0,6+4)=(0,10)$$

# 2013 April(71G) Math Question 10

Choice G

$$21=3\times7$$ $$6=2\times3$$ $$4=2\times2$$ $$\Rightarrow 2\times2\times3\times7=84$$

# 2013 April(71G) Math Question 11

Choice A

$$89\times5=445$$ $$445-78-92-96-94=85$$

# 2013 April(71G) Math Question 12

Choice H

$$\frac{2520}{12\times14}=15$$

# 2013 April(71G) Math Question 13

Choice D

$$15-(x\times f+x\times h)$$ $$=15-x(f+h)$$

# 2013 April(71G) Math Question 14

Choice H

$$=\mid-48+6\mid=\mid-42\mid=42$$

# 2013 April(71G) Math Question 15

Choice E

$$The\ area\ of\ a\ circle=\pi r^{2}$$ $$\Rightarrow \pi R^{2}-3\pi r^{2}$$

# 2013 April(71G) Math Question 16

Choice H

$$y=50$$ $$x+y=180$$ $$\Rightarrow x=130$$ $$x-y=130-50=80$$

# 2013 April(71G) Math Question 17

Choice B

$$3x-5\geq 7$$ $$\Rightarrow 3x\geq7+5$$ $$\Rightarrow x\geq \frac{7+5}{3}$$ $$\Rightarrow x\geq \frac{12}{3}$$ $$\Rightarrow x\geq 4$$

# 2013 April(71G) Math Question 18

Choice K

$$s(-3)=3(-3)^{2}-5$$ $$=3(9)-5$$ $$=27-5$$ $$=22$$

# 2013 April(71G) Math Question 19

Choice C

$$\angle WCZ-\angle WCY$$ $$150°-100°=50°=\angle YCZ$$ $$\angle XCY=\angle XCZ-\angle YCZ$$ $$=80°-50°=30°$$

# 2013 April(71G) Math Question 20

Choice G

$$500\div200=2.5$$ $$6\div2.5=2.4$$

# 2013 April(71G) Math Question 21

Choice A

$$\frac{27}{5}=5.4$$ $$\frac{24}{6}=4$$ $$\frac{20}{4}=5$$ $$4\times500=2000$$

# 2013 April(71G) Math Question 22

Choice H

$$(7+6)s+(8+6.5)f+(5.5+5)b$$ $$=13s+14.5f+10.5b$$

# 2013 April(71G) Math Question 23

Choice B

$$5a=3---(1)$$ $$2a+3b=5---(2)$$ $$(2)\times5-(1)\times2$$ $$\Rightarrow (10a+15b)-(10a)=5\times5-3\times2$$ …

# 2013 April(71G) Math Question 24

Choice H

$$24\times150=3600$$ $$4\times60=240$$ $$3600\div240=15$$

# 2013 April(71G) Math Question 25

Choice E

$$7-(-4)x^{2}-6x+(5-3)$$ $$=11x^{2}-6x+2$$

# 2013 April(71G) Math Question 26

Choice J

$$(x^{2})^{3}(x^{4})^{5}=x^{a}$$ $$=x^{2\times3+4\times5}=x^{a}$$ $$6+20=a$$ $$a=26$$

# 2013 April(71G) Math Question 27

Choice D

$$\frac{0.003}{100}=0.0003$$

# 2013 April(71G) Math Question 28

Choice H

$$2500\times0.15=375$$

# 2013 April(71G) Math Question 29

Choice D

$$45+5+15+5=70$$

# 2013 April(71G) Math Question 30

Choice F

$$200\times0.45=90$$ $$\Rightarrow \frac{90}{200}=0.45$$ $$\Rightarrow \frac{90+15}{200+25}=\frac{105}{225}$$

# 2013 April(71G) Math Question 31

Choice C

$$4y+11y=15y$$ $$y=\frac{180}{15}=12$$ $$4y=48$$ $$\angle B=180°-43°-48°=89°$$

# 2013 April(71G) Math Question 32

Choice F

$$x-\sqrt{5}=0$$ $$x=\sqrt{5}$$ $$y-1=0$$ $$y=1$$

# 2013 April(71G) Math Question 33

Choice E

$$\tan 31°=\frac{?}{103}$$ $$?=\tan 31°103$$

# 2013 April(71G) Math Question 34

Choice J

y=4 is a line parallel …

# 2013 April(71G) Math Question 35

Choice B

$$2x+3y=12---(line\ l)$$ $$\Rightarrow y=-\frac{2}{3}x+4$$ $$y=(-\frac{2}{3}\times2)x+(4-3)$$ …

Choice H

# 2013 April(71G) Math Question 37

Choice C

$$5r\times2r=90$$ $$10r^{2}=90$$ $$r^{2}=9$$ $$r=3$$ $$3\times5=15$$

# 2013 April(71G) Math Question 38

Choice G

As time elapses, the distance …

# 2013 April(71G) Math Question 39

Choice B

$$2\times2\times(1\frac{1}{4})+(1\frac{1}{4})(1\frac{1}{4})$$ $$5+\frac{25}{16}$$ $$=6+\frac{9}{16}$$

Choice K

Choice D

# 2013 April(71G) Math Question 42

Choice K

$$\frac{2x-y}{x+y}=\frac{3}{4}$$ $$4(2x-y)=3(x+y)$$ $$8x-4y=3x+3y$$ $$5x=7y$$ $$\frac{x}{y}=\frac{7}{5}$$

# 2013 April(71G) Math Question 43

Choice C

$$8:7=5:?$$ $$\frac{8}{7}=\frac{5}{?}$$ $$8\times?=5\times7$$ $$?=\frac{35}{8}=4\frac{3}{8}$$

# 2013 April(71G) Math Question 44

Choice H

The formula is BMI = …

# 2013 April(71G) Math Question 45

Choice E

$$15^{2}-5^{2}=\overline{AD}^{2}$$ $$225-25=200=\overline{AD}^{2}$$ $$\overline{AD}=\sqrt{200}=10\sqrt{2}$$

# 2013 April(71G) Math Question 46

Choice G

$$\triangle\times4+\Box$$ $$\Rightarrow\triangle=10\times12\times\frac{1}{2}=60$$ $$\Rightarrow\Box =10\times10=100$$ $$\triangle\times4+\Box=60\times4+100=340$$

# 2013 April(71G) Math Question 47

Choice D

$$(12+24)\times16\times\frac{1}{2}$$ $$=36\times16\times\frac{1}{2}$$ $$=288$$ $$\frac{288}{90}=3...18$$

Marie …

# 2013 April(71G) Math Question 48

Choice F

$$3a°\lt90°$$ $$a\lt30$$

# 2013 April(71G) Math Question 49

Choice C

$$Correct\rightarrow 2x$$ $$Incorrect\rightarrow x$$ $$30+10(2x)-5(x)=150$$ …

# 2013 April(71G) Math Question 50

Choice F

$$f(x)=\frac{2x+b}{x+a}$$ $$=\frac{2x}{x+a}+\frac{b}{x+a}$$ $$=\frac{2}{1+\frac{a}{x}}+\frac{\frac{b}{x}}{1+\frac{a}{x}}$$ $$\lim_{\frac{a}{x}\rightarrow0}\frac{2}{1+\frac{a}{x}}=2$$ $$\lim_{\frac{b}{x}\rightarrow0}\frac{\frac{b}{x}}{1+\frac{a}{x}}=0$$

# 2013 April(71G) Math Question 51

Choice B

$$-0.43\lt-0.423\lt-0.42$$ $$\Rightarrow -\frac{43}{100}\lt-0.423\lt-\frac{42}{100}$$ $$n=-43$$

# 2013 April(71G) Math Question 52

Choice F

$$\frac{51+53}{2}=52$$

# 2013 April(71G) Math Question 53

Choice D

$$\frac{25}{3}\pi=\frac{25\times180°}{3}=1500°$$ $$1500°=360°\times4+60°$$

# 2013 April(71G) Math Question 54

Choice J

$$(6-7i)(\pi+6i)$$ $$=6\pi+36i-7i\pi+42$$ $$=(J)$$

Choice A