# 2011 December(70A) Math Question 1

- Cost

Choice E

$$16\times0.2=3.2$$

# 2011 December(70A) Math Question 2

Choice J

$$\frac{15}{3.25}=\frac{10.4}{x}$$ $$15x=10.4\times3.25=33.8$$ $$x=\frac{33.8}{15}=2.25$$

# 2011 December(70A) Math Question 3

Choice C

$$4x-6x=-7+11$$ $$-2x=4$$ $$x=-2$$

# 2011 December(70A) Math Question 4

Choice H

$$9\times40+9(1\frac{1}{2})(3)$$ $$=360+40.5$$ $$=400.5$$

# 2011 December(70A) Math Question 5

Choice D

$$\Rightarrow 90\times13+n\times15$$

# 2011 December(70A) Math Question 6

Choice K

$$10\times20\times14=2800$$

# 2011 December(70A) Math Question 7

Choice A

$$2(3)^{2}(-5)-5(3)(4)^{2}$$ $$=2(9)(-5)-5(3)(16)$$ $$=-90-240$$ $$=-330$$

# 2011 December(70A) Math Question 8

Choice J

$$(2\times4)(x^{3+5}y^{1+3})$$ $$=8x^{8}y^{4}$$

# 2011 December(70A) Math Question 9

Choice B

$$4-\frac{1}{4}-1\frac{1}{2}$$ $$=4-\frac{1}{4}-1\frac{2}{4}$$ $$=2\frac{1}{4}$$

# 2011 December(70A) Math Question 10

Choice G

$$=9-35$$ $$=-26$$

# 2011 December(70A) Math Question 11

Choice B

$$\angle BDC=90°-\angle CBD$$ $$\angle CBD=180°-25°-30°=55°$$ $$\Rightarrow \angle BDC=90°-55°=35°$$

# 2011 December(70A) Math Question 12

Choice H

$$2x+9y=-18$$ $$\Rightarrow y=-\frac{2}{9}x-2$$ $$m=-\frac{2}{9}$$

# 2011 December(70A) Math Question 13

Choice D

$$0.0000378=\frac{378}{10000000}=378\times10^{-7}$$

# 2011 December(70A) Math Question 14

Choice F

When two numbers (or variables) are multiplied together within parentheses, the exponent the quantity in the parentheses is raised to can be distributed to both terms.

$$xy^{a}=x^{a}y^{a}$$

# 2011 December(70A) Math Question 15

Choice A

$$=(x-4)(x+3)$$

# 2011 December(70A) Math Question 16

Choice G

$$\overline{PQ}:\overline{QR}=3:8$$ $$\overline{PQ}:\overline{PR}=3:3+8=3:11$$

# 2011 December(70A) Math Question 17

Choice A

$$(A) 5^{2}-13=25-13=12$$

# 2011 December(70A) Math Question 18

Choice K

$$45-45-90 triangle=1:1:\sqrt{2}$$ $$\overline{AC}=10\sqrt{2}=\sqrt{200}$$

# 2011 December(70A) Math Question 19

Choice A

$$3x+y+4=14+2x$$ $$y=14-4+2x-3x=10-x$$ $$\Rightarrow y=-x+10$$

# 2011 December(70A) Math Question 20

Choice K

$$\overline{AC}=\frac{5}{6}\overline{JK}=\frac{5}{6}\times18=15$$ $$\frac{5}{6}=\frac{x}{18}\Rightarrow x=15$$

# 2011 December(70A) Math Question 21

Choice E

Since the cost of each …

# 2011 December(70A) Math Question 22

Choice K

$$2,650\times2=5,330$$ $$5,330\div400=13.25$$

# 2011 December(70A) Math Question 23

Choice B

If the hour hand of …

# 2011 December(70A) Math Question 24

Choice G

$$(4\times4)+(3\times4\times\frac{1}{2})$$ $$=16+6$$ $$=22$$

# 2011 December(70A) Math Question 25

Choice E

Look for a point that …

# 2011 December(70A) Math Question 26

Choice K

The table contains 11 scores …

# 2011 December(70A) Math Question 27

Choice E

The range of the scores …

# 2011 December(70A) Math Question 28

Choice G

$$(85+86+87+88+89+100)\div6=89.167$$ $$(88+80+100+99+98+x)\div6\gt89.167$$ $$(465+x)\div6\gt89.167$$ $$(465+x)\gt535$$ $$x\gt70$$

# 2011 December(70A) Math Question 29

Choice D

By definition, a linear pair …

# 2011 December(70A) Math Question 30

- FOIL

Choice F

$$=\frac{(x-11)(x-11)}{(x+11)(x-11)}$$ $$=\frac{(x-11)}{(x+11)}$$

# 2011 December(70A) Math Question 31

Choice B

$$12x^{2}=28x$$ $$x(12x-28)=0$$ $$x=0$$ $$12x=28$$ $$x=\frac{28}{12}=\frac{7}{3}$$

# 2011 December(70A) Math Question 32

Choice H

If “all blins are meeps,” …

Choice C

Choice C

# 2011 December(70A) Math Question 42

Choice H

l: the length of the …

# 2011 December(70A) Math Question 43

Choice B

You can set the denominator …

# 2011 December(70A) Math Question 44

Choice K

$$\frac{135}{6}=22...3$$ $$0.\overline{428571}$$

The third number …

# 2011 December(70A) Math Question 45

Choice D

There are two things that …

Choice F

# 2011 December(70A) Math Question 57

Choice A

$$\frac{a}{b}=\frac{7}{11}$$ $$\Rightarrow a:b=7:11$$ $$a=7r,\ b=11r$$ …

# 2011 December(70A) Math Question 58

Choice F

The volume of a rectangular …

# 2011 December(70A) Math Question 59

Choice C

$$\log_{a}{x}+\log_{a}{y}=\log_{a}{xy}$$ $$\log_{}{(x-2)x}=\log_{}{x^{2}-2x}$$

# 2011 December(70A) Math Question 60

Choice J

The median score is the …