Choice B

# 2010 April(68G) Math Question 2

Choice H

$$=8+20x+9-2x$$ $$=18x+17$$

# 2010 April(68G) Math Question 3

Choice C

$$(-2,8)+(8,-2)=(6,6)$$

# 2010 April(68G) Math Question 4

Choice K

$$=17\times70+20\times n$$

# 2010 April(68G) Math Question 5

- Cost

Choice C

$$\frac{60}{80}=0.75$$

# 2010 April(68G) Math Question 6

Choice F

$$180-114=66$$ $$66\div2=33$$

# 2010 April(68G) Math Question 7

Choice E

$$P=\frac{blue+yellow}{28}$$ $$=\frac{8+4}{28}$$ $$=\frac{12}{28}$$ $$=\frac{3}{7}$$

# 2010 April(68G) Math Question 8

Choice G

$$\frac{60}{1\frac{1}{2}}$$ $$=\frac{60}{\frac{3}{2}}$$ $$=60\times\frac{2}{3}$$ $$=40$$

# 2010 April(68G) Math Question 9

Choice D

$$62\ is\ the\ lowest\ score.$$ $$(78+83+86+93)\div4=85$$

# 2010 April(68G) Math Question 10

Choice F

$$5y=m-n$$ $$y=\frac{m-n}{5}$$

# 2010 April(68G) Math Question 11

Choice D

$$5+2x=19$$ $$2x=19-5=14$$ $$x=7$$ $$3x=21$$

# 2010 April(68G) Math Question 12

Choice H

$$\frac{24}{4}=6$$ $$6\times6=36$$

# 2010 April(68G) Math Question 13

Choice C

$$7\times10^{-2}\times4.58\times 10^{6}$$ $$=32.06\times10^{4}$$ $$=320600$$

# 2010 April(68G) Math Question 14

Choice G

$$=(x-4)(x-2)$$

# 2010 April(68G) Math Question 15

Choice D

$$c\lt d,\ e\lt c,\ e\gt b,\ b\gt a$$ $$\Rightarrow a\lt b \lt e\lt c \lt d$$

# 2010 April(68G) Math Question 16

Choice F

$$=\frac{2\times4+1\times6}{2\times1-4\times6}$$ $$=\frac{8+6}{2-24}$$ $$=\frac{14}{-22}$$ $$=\frac{7}{-11}$$

# 2010 April(68G) Math Question 17

Choice B

$$red:\ r,\ blue:\ b$$ $$Lance=3\ medium+3\ large$$ $$medium=5r+3b$$ $$large=10r+5b$$ $$Lance=3(5r+3b)+3(10r+5b)$$ $$=15r+9b+30r+15b$$ $$=45r+24b$$ $$\Rightarrow 24\ blue$$

# 2010 April(68G) Math Question 18

Choice J

$$80=2^{4}\times5$$ $$70=2\times5\times7$$ $$30=2\times3\times5$$ $$[L.C.M]=2^{4}\times3\times5\times7=1680$$

# 2010 April(68G) Math Question 19

Choice B

$$It's\ a\ 5-12-13\ triangle.$$ $$(5+12)-13=4$$

# 2010 April(68G) Math Question 20

Choice K

$$(a^{8})^{24}$$ $$=a^{8\times24}$$ $$=a^{192}$$

# 2010 April(68G) Math Question 21

Choice D

$$h(-3)$$ $$=4(-3)^{2}-3(-3)$$ $$=36+9$$ $$=45$$

# 2010 April(68G) Math Question 22

- Cost

Choice K

$$\Rightarrow p-0.3p$$

# 2010 April(68G) Math Question 23

Choice B

$$1.29\times\frac{2}{5}=0.516$$

Choice K