Question 20: In an arithmetic progression, the first term is 2, and the sum of the 1st and 6th terms is 16.5. What is the 4th term? Question 21: The angle of a sector of a circle of diameter 8cm is $135^{\circ}$. Find the area of the sector. (Take $\pi = \frac{22}{7}$). Question 22: Simplify $36^{\frac{1}{2}} \times 64^{-\frac{1}{3}} \times 5^0$. Question 23: The number 186047 was corrected to 186,000. Which of the following can correctly describe the degree of approximation mode? I. To the nearest hundred II. To the nearest thousand III. To 3 significant figures IV. To 4 significant figures Question 24: A student is told to draw the graph of $y = x^2 + 4x - 6$. He is then told to draw a linear graph on the same axis such that the intersection of the two graphs will give the solutions to the equation $x^2 + 4x - 7 = 0$. What is the... (The rest of the question is cut off).

AlgebraArithmetic ProgressionGeometryArea of SectorExponentsSignificant FiguresQuadratic EquationsGraphing
2025/6/5

1. Problem Description

Question 20: In an arithmetic progression, the first term is 2, and the sum of the 1st and 6th terms is 16.

5. What is the 4th term?

Question 21: The angle of a sector of a circle of diameter 8cm is 135135^{\circ}. Find the area of the sector. (Take π=227\pi = \frac{22}{7}).
Question 22: Simplify 3612×6413×5036^{\frac{1}{2}} \times 64^{-\frac{1}{3}} \times 5^0.
Question 23: The number 186047 was corrected to 186,
0
0

0. Which of the following can correctly describe the degree of approximation mode?

I. To the nearest hundred
II. To the nearest thousand
III. To 3 significant figures
IV. To 4 significant figures
Question 24: A student is told to draw the graph of y=x2+4x6y = x^2 + 4x - 6. He is then told to draw a linear graph on the same axis such that the intersection of the two graphs will give the solutions to the equation x2+4x7=0x^2 + 4x - 7 = 0. What is the... (The rest of the question is cut off).

2. Solution Steps

Question 20:
Let a1a_1 be the first term and ana_n be the nth term of an arithmetic progression. Let dd be the common difference. We are given that a1=2a_1 = 2 and a1+a6=16.5a_1 + a_6 = 16.5.
The nth term of an arithmetic progression is given by an=a1+(n1)da_n = a_1 + (n-1)d. Thus, a6=a1+5d=2+5da_6 = a_1 + 5d = 2 + 5d.
We have a1+a6=2+(2+5d)=4+5d=16.5a_1 + a_6 = 2 + (2 + 5d) = 4 + 5d = 16.5.
So, 5d=16.54=12.55d = 16.5 - 4 = 12.5.
Then, d=12.55=2.5d = \frac{12.5}{5} = 2.5.
We want to find the 4th term, a4=a1+3d=2+3(2.5)=2+7.5=9.5a_4 = a_1 + 3d = 2 + 3(2.5) = 2 + 7.5 = 9.5.
Question 21:
The radius of the circle is half the diameter, so r=82=4r = \frac{8}{2} = 4 cm.
The area of the sector is given by the formula:
Area =θ360×πr2= \frac{\theta}{360^{\circ}} \times \pi r^2, where θ\theta is the angle of the sector.
Area =135360×227×42=38×227×16=3×22×27=1327=1867 cm2= \frac{135^{\circ}}{360^{\circ}} \times \frac{22}{7} \times 4^2 = \frac{3}{8} \times \frac{22}{7} \times 16 = \frac{3 \times 22 \times 2}{7} = \frac{132}{7} = 18 \frac{6}{7} \text{ cm}^2.
Question 22:
3612×6413×50=36×1643×1=6×14×1=64=32=11236^{\frac{1}{2}} \times 64^{-\frac{1}{3}} \times 5^0 = \sqrt{36} \times \frac{1}{\sqrt[3]{64}} \times 1 = 6 \times \frac{1}{4} \times 1 = \frac{6}{4} = \frac{3}{2} = 1 \frac{1}{2}.
Question 23:
186047 corrected to
1
8
6
0
0

0. I. Nearest hundred: 186047 rounded to the nearest hundred is

1
8
6
0
0

0. True.

II. Nearest thousand: 186047 rounded to the nearest thousand is
1
8
6
0
0

0. True.

III. 3 significant figures: 186047 rounded to 3 significant figures is
1
8
6
0
0

0. True.

IV. 4 significant figures: 186047 rounded to 4 significant figures is
1
8
6
0
0

0. True.

All statements are correct.
Question 24:
We are given y=x2+4x6y = x^2 + 4x - 6 and x2+4x7=0x^2 + 4x - 7 = 0.
The equation x2+4x7=0x^2 + 4x - 7 = 0 can be obtained by subtracting 1 from the equation y=x2+4x6y = x^2 + 4x - 6, so y1=x2+4x7=0y - 1 = x^2 + 4x - 7 = 0.
Thus, y=1y = 1. The linear graph is y=1y = 1.

3. Final Answer

Question 20: B. 9.5 (Note: This was not an option, therefore there may have been an error in the question.) This number does not match any given answer, but is closest to B. 9.
2.
Question 21: C. 1867 cm218 \frac{6}{7} \text{ cm}^2
Question 22: D. 1121 \frac{1}{2}
Question 23: A. All of them
Question 24: The linear graph is y =
1.