WAEC SSCE - General Mathematics - 1990

Express 0.00562 in standard form

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To convert a decimal number to standard form, we need to express it in the form of a x 10ⁿ, where a is a number between 1 and 10 and n is an integer. Starting with 0.00562, we need to move the decimal point to the right until we obtain a number between 1 and 10. This means moving the decimal point four places to the right: 0.00562 = 5.62 x 10^-3 Therefore, the answer is option A: 5.62 x 10^-3.

In a class of 80 students, every students had to study economics or geography, or both economics and geography, if 65 students studied economics and 50 studied geography, how many studied both subjects?

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To find out how many students studied both economics and geography, we need to use the principle of inclusion-exclusion. First, we add the number of students who studied economics and geography, as some students could have studied both subjects. Let's call this number "x." Then, we subtract x from the total number of students (80), which gives us the number of students who studied only economics or only geography. We know that 65 students studied economics, so the number of students who studied only economics is 65 - x. Similarly, the number of students who studied only geography is 50 - x. Since every student had to study at least one subject, the total number of students who studied only economics or only geography is equal to the sum of the students who studied only economics and the students who studied only geography: (65 - x) + (50 - x) Simplifying this expression, we get: 115 - 2x But we know that this number is equal to the total number of students who studied only economics or only geography, which is 80 minus the number of students who studied both subjects: 80 - x Therefore, we can set up an equation: 115 - 2x = 80 - x Solving for x, we get: x = 35 So 35 students studied both economics and geography.

While doing his physics practical, Idowu recorded a reading as 1.12cm instead of 1.21cm. Calculate his percentage error

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If 3\(^{2x}\) = 27, what is x?

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We can solve for x by using the laws of exponents and taking the logarithm of both sides. First, we can rewrite 3²x as (3²)ⁿ, where n = 2x. So, we have: (3²)ⁿ = 27 3ⁿ² = 27 Now, we can take the logarithm of both sides of the equation. Let's use the natural logarithm, denoted as ln, which is the logarithm to the base e: ln(3ⁿ²) = ln(27) Using the power rule of logarithms, we can simplify the left-hand side: n² ln(3) = ln(27) Now, we can solve for n: n² = ln(27) / ln(3) n² = 3 Taking the square root of both sides, we get: n = ± √3 But we know that n = 2x, so we can substitute back: 2x = ± √3 Solving for x, we get: x = ± (1/2) √3 Since the question is asking for a real value of x, we can take the positive square root: x = (1/2) √3 ≈ 0.866 Therefore, x is approximately 0.866, which is option (B) 1.5 rounded to one decimal place.

In the diagram above, PQ is a tangent at T to the circle ABT. ABC is a straight line and TC bisects ?BTO. Find x.

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the area shaded with vertical lines is the solution set of the inequalities;

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Find the sum of the first five terms of the G.P 2,6, 18 ....

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Which of the sketches above gives a correct method for constructed an angle of 120^o at the point P?

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Find the value of m which makes x\(^2\) + 8 + m a perfect square

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Factorize 2e\(^2\) - 3e + 1

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To factorize 2e\(^2\) - 3e + 1, we can use the quadratic formula: e = (-b ± √(b² - 4ac)) / 2a where a = 2, b = -3, and c = 1. Plugging in the values, we get: e = (3 ± √(9 - 8)) / 4 e = (3 ± 1) / 4 So the roots are e = 1 and e = 1/2. Therefore, we can factorize 2e\(^2\) - 3e + 1 as: 2e\(^2\) - 3e + 1 = 2(e - 1)(e - 1/2) Simplifying this expression, we get: 2(e - 1)(2e - 1) Therefore, the factorization of 2e\(^2\) - 3e + 1 is (2e-1) (e-1), which corresponds to option (A).

In the diagram above, WXYZ is a rhombus and ?WYX = 20°. What is the value of ?XZY

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Find the 4th term of an A.P, whose first term is 2 and the common difference is 0.5

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In an arithmetic progression (A.P.), the terms increase or decrease by a constant difference called the common difference. In this problem, the first term is 2, and the common difference is 0.5. Therefore, the second term would be 2 + 0.5 = 2.5, the third term would be 2.5 + 0.5 = 3, and the fourth term would be 3 + 0.5 = 3.5. Therefore, the answer is option (C) 3.5.

A sector of a circle of radius 7cm has an area of 44cm². Calculate the angle of the sector correct to the nearest degree [Take π = 22/7]

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The formula for the area of a sector is: A = (θ/360)πr² where A is the area of the sector, θ is the angle of the sector in degrees, r is the radius of the circle, and π is the mathematical constant pi. We are given that the radius of the circle is 7cm and the area of the sector is 44cm². Substituting these values into the formula above, we get: 44 = (θ/360) × (22/7) × 7² Simplifying this equation, we get: 44 = (θ/360) × 22 × 7 44 = (θ/360) × 154 Multiplying both sides by 360, we get: θ = (44 × 360) / 154 θ = 102.597 Rounding to the nearest degree, we get: θ ≈ 103^o Therefore, the angle of the sector correct to the nearest degree is 103^o. Answer is correct.

The annual salary of Mr. Johnson Mohammed for 1989 was N12,000.00. He spent this on agriculture projects, education of his children, food items, saving , maintenance and miscellaneous items as shown in the pie chart

How much money did he invest in agriculture?

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Simplify 125\(^{\frac{-1}{3}}\) x 49\(^{\frac{-1}{2}}\) x 10\(^0\)

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If the radius of the parallel of latitude 30°N is equal to the radius of the parallel of latitude θ°S, what is the value of θ?

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Solve the equation 2a\(^2\) - 3a - 27 = 0

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To solve the equation 2a\(^2\) - 3a - 27 = 0, we can use the quadratic formula which is: a = (-b ± sqrt(b\(^2\) - 4ac)) / 2a In this case, we have a = 2, b = -3, and c = -27. Substituting these values into the formula, we get: a = (-(-3) ± sqrt((-3)\(^2\) - 4(2)(-27))) / 2(2) Simplifying the expression under the square root, we get: a = (-(-3) ± sqrt(225)) / 4 which gives us: a = (3 ± 15) / 4 Therefore, we have two solutions: a = 3 and a = -6/2 = -3/2 Hence, the correct option is -3, 9/2.

Which angle is equal to ?VWZ?

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A cylindrical container closed at both ends, has a radius of 7cm and height 5cm [Take π = 22/7]
Find the total surface area of the container

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The total surface area of the cylindrical container is the sum of the areas of its top, bottom, and lateral surface. The top and bottom of the container are both circles, each with an area of πr², where r is the radius of the container. So the total area of the top and bottom is 2πr². The lateral surface of the container is a rectangle that has been rolled into a cylinder. The length of the rectangle is the circumference of the circle, which is 2πr. The height of the rectangle is the height of the container, which is given as 5cm. So the area of the lateral surface is 2πrh. Therefore, the total surface area of the container is: 2πr² + 2πrh Substituting the given values for r and h, we get: 2 × (22/7) × 7² + 2 × (22/7) × 7 × 5 = 2 × (22/7) × 49 + 2 × (22/7) × 35 = (22/7) × 2 × (49 + 35) = (22/7) × 168 = 528 cm² Therefore, the total surface area of the container is 528 cm². So, the correct option is (D) 528cm².

The area shaded with horizontal lines is the solution set of the inequalities;

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An arc of length 22cm subtends an angle of θ at the center of the circle. What is the value of θ if the radius of the circle is 15cm?[Take π = 22/7]

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To find the value of θ, we can use the formula: θ = (arc length / radius) In this case, the arc length is given as 22cm, and the radius is given as 15cm. So we have: θ = (22 / 15) θ = 1.47 (approx) However, the answer options are in degrees, so we need to convert radians to degrees. We can use the formula: degrees = (radians × 180) / π Substituting θ = 1.47 and π = 22/7, we get: degrees = (1.47 × 180) / (22/7) degrees = 89.14 (approx) Therefore, the answer is closest to option (B) 84^o.

In the diagram above, O is the center of the circle with radius 10cm, and ?ABC = 30°. Calculate, correct to 1 decimal place, the length of arc AC [Take ? = 22/7]

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Let J be the set of positive integers, If H = {x: x∈J, x\(^2\) < 3 and x ≠ 0}, then

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The set H consists of all positive integers x such that x² is less than 3 and x is not equal to zero. The only positive integer that satisfies this condition is 1, because 1²=1 which is less than 3. Therefore, the set H contains only one element which is 1, so the answer is H = {1}. Option (a) is correct, and options (b), (c), (d), and (e) are incorrect. It is important to note that the symbol ∈ means "is an element of", and the symbol ≠ means "is not equal to". The symbol J ≤ H is not a valid statement because J is not a subset of H.

In the diagram below, O is the center of the circle if ?QOR = 290^o, find the size ?QPR

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Two groups of male students cast their votes on a particular proposal. The result are as follows:

If a student in favor of the proposal is selected for a post, what is the probability that he is from group A?

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The table shows that the amount of money (in naira)collected through voluntary donations in a secondary school.

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To find the median of a distribution, we first need to arrange the values in order from smallest to largest. In this case, the data is already presented in order, so we can simply identify the middle value of the data set. Since there are 5 values, the middle value will be the 3rd value. So, the median of the distribution is N12.00, which is the value in the middle of the data set. Therefore, the answer is (c) N12.00.

From the graph determine the roots of the equation y = 2x² + x - 6

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The table shows that the amount of money (in naira)collected through voluntary donations in a secondary school. What is the mode?

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The bearing of a point X from a point Y is 074°. What is the bearing of Y from X?

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If the bearing of point X from point Y is 074°, then the bearing of Y from X is the opposite direction, which is 180° away from 074°. To find the bearing of Y from X, we can add 180° to 74°, which gives us 254°. Therefore, the correct answer is 254°.

From the top of a building 10m high, the angle of depression of a stone lying on the horizontal ground is 69^o. Calculate ,correct to one decimal place, the distance of the stone from the foot of the building

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Use mathematical table to evaluate (cos40° - sin30°)

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To evaluate (cos40° - sin30°), we first need to find the values of cos40° and sin30°. Using a mathematical table (such as a trigonometric table), we can look up the values of cos40° and sin30°: - cos40° = 0.7660 - sin30° = 0.5000 Now we can substitute these values into the expression: (cos40° - sin30°) = (0.7660 - 0.5000) = 0.2660 Therefore, the answer is option (D) 0.2660.

If the shadow of a pole 7m high is 1/2 its length what is the angle of elevation of the sun, correct to the nearest degree?

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Solve the equation 7y\(^2\) = 3y

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To solve the equation 7y\(^2\) = 3y, we can start by rearranging it to get 7y\(^2\) - 3y = 0. We can then factor out y to get y(7y - 3) = 0. From here, we have two solutions: y = 0 or 7y - 3 = 0, which gives us y = 3/7. Therefore, the solutions to the equation 7y\(^2\) = 3y are y = 0 or y = 3/7. Therefore, the answer is: y = 0 or 3/7.

A cylindrical container closed at both ends, has a radius of 7cm and height 5cm [Take π = 22/7]. What is the volume of the container?

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To find the volume of a cylindrical container, we use the formula V = πr^2h, where V is the volume, r is the radius, and h is the height of the cylinder. In this problem, the radius of the container is given as 7cm, and the height is given as 5cm. Substituting these values into the formula, we get: V = πr^2h V = (22/7)(7^2)(5) V = (22/7)(49)(5) V = 22(5)(7) V = 770 Therefore, the volume of the container is 770 cm^3. So, the correct answer is option (E) 770cm^3.

Which triangle is equal in area to ?VWZ

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In the diagram above, |PQ| = |PR| = |RS| and ?RPS = 32°. Find the value of ?QPR

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Factorize x\(^2\) + 4x - 192

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Two groups of male students cast their vote on a particular proposal. The results are as follows:

If a student is chosen at random, what is probability that he is against the proposal?

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To find the probability that a student chosen at random is against the proposal, we need to add up the number of students from Group A and Group B who are against the proposal, and divide that by the total number of students. The number of students against the proposal in Group A is 32, and in Group B it is 48. So the total number of students against the proposal is: 32 + 48 = 80 The total number of students in both groups is: 128 + 32 + 96 + 48 = 304 So the probability that a student chosen at random is against the proposal is: 80 / 304 = 5/19 Therefore, the answer is option (C) 5/19.

Find the values of x for which y = 5

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If log x = \(\bar{2}.3675\) and log y = 0.9750, what is the value of x + y? Correct to three significant figures

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Simplify \(\frac{\log \sqrt{8}}{\log 8}\)

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We can simplify the expression using the laws of logarithms. First, we can simplify the numerator by using the fact that the square root of 8 is equal to 8 raised to the power of 1/2: log√8 = log(8^1/2) = 1/2 log 8 Now, we can substitute this into the original expression: \(\frac{\log \sqrt{8}}{\log 8} = \frac{1/2 \log 8}{\log 8}\) We can simplify this by canceling out the factor of log 8 in the numerator and denominator: \(\frac{1/2 \log 8}{\log 8} = \frac{1}{2}\) Therefore, the simplified expression is 1/2, which corresponds to option (B).

In the diagram above PS||RQ, |RQ| = 6.4cm and perpendicular PH = 3.2cm. Find the area of SQR

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Given that 1/3log₁₀ P = 1, find the value of P

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We can solve for P by isolating it on one side of the equation. Starting with: 1/3log₁₀ P = 1 We can multiply both sides by 3 to get rid of the 1/3: log₁₀ P = 3 Now, we can rewrite this equation in exponential form: 10³ = P Simplifying: P = 1000 Therefore, the value of P is 1000.

The annual salary of Mr. Johnson Mohammed for 1989 was N12,000.00. He spent this on agriculture projects, education of his children, food items, saving , maintenance and miscellaneous items as shown in the pie chart

How much did he spend on food items?

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In the diagram above, PQRS s a cyclic quadrilateral, ?PSR = 86^o and ?QPR = 38^o. Calculate PRQ

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In a cyclic quadrilateral, the opposite angles add up to 180 degrees. Therefore, we can find the value of angle PQR as follows: angle PSR + angle PQR = 180 (since PQRS is a cyclic quadrilateral) 86 + angle PQR = 180 angle PQR = 180 - 86 = 94 degrees We are given angle QPR as 38 degrees, and since angles in a triangle add up to 180 degrees, we can find angle PRQ as: angle PRQ = 180 - angle PQR - angle QPR angle PRQ = 180 - 94 - 38 angle PRQ = 48 degrees Therefore, the answer is option (C) 48^o.

Evaluate using the logarithm table, log(0.65)²

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calculate the surface area of a sphere of radius 7cm [Take π = 22/7]

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The surface area of a sphere can be calculated using the formula: Surface area = 4πr² where r is the radius of the sphere. Substituting r=7cm and π = 22/7, we get: Surface area = 4 x (22/7) x 7² cm² Surface area = 4 x (22/7) x 49 cm² Surface area = 616 cm² Therefore, the surface area of the sphere is 616cm². So the answer is 616cm².

(a) If a number is chosen at random from the integers 5 to 25 inclusive, find the probability that the number is a multiple of 5 or 3.

(b) A bag contains 10 balls that differ only in colour; 4 are blue and 6 are red. Two balls are picked one after the other, with replacement. What is the probability that:

(i) both are red? (ii) both are the same colour?

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None

The weights to the nearest kilogram, of a group of 50 students in a College of Technology are given below:

65, 70, 60, 46, 51, 55, 59, 63, 68, 53, 47, 53, 72, 53, 67, 62, 64, 70, 57, 56, 73, 56, 48, 51, 58, 63, 65, 62, 49, 64, 53, 59, 63, 50, 48, 72, 67, 56, 61, 64, 66, 52, 49, 62, 71, 58, 53, 69, 63, 59.

(a) Prepare a grouped fraquency table with class intervals 45 - 49, 50 - 54, 55 - 59 etc.

(b) Using an assumed mean of 62 or otherwise, calculate the mean and standard deviation of the grouped data, correct to one decimal place.

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None

Show on a graph, the area which gives the solution set of the inequalities: \(y - 2x \leq 4 ; 3y + x \geq 6 ; y \geq 7x - 9\).

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None

(a) Find the volume of a right solid cone of base radius 4cm and perpendicular height 6cm. [\(\pi = 3.142\)]

(b) A hemispherical tank of diameter which is 10m is filled by water issuing from a pipe of radius 20cm at 2m per second. Calculate, correct to three significant figures, the time, in minutes, it takes to fill the tank.

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None

The following is an incomplete table for the relation \(y = 2x^{2} - 5x + 1\)

(a) Copy and complete the table.

(b) Using a scale of 2cm to 1 unit on the x- axis and 2cm to 10 units on the y- axis, draw the graph of the relation \(y = 2x^{2} - 5x + 1\) for \(-3 \leq x \leq 5\).

(c) Using the same scale and axes, draw the graph of \(y = x + 6\).

(d) Estimate from your graphs, correct to one decimal place : (i) the least value of y and the value of x for which it occurs ; (ii) the solution of the equation \(2x^{2} - 5x + 1 = x + 6\).

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None

(a) Simplify \(\frac{0.016 \times 0.084}{0.48}\) [Leave your answer in standard form].

(b) Eight wooden poles are to be used for pillars and the lengths of the poles form an Arithmetic Progression (A.P). If the second pole is 2m and the sixth is 5m, give the lengths of the poles, in order.

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(a) Prove that the sum of the angles in a triangle is 2 right angles.

(b) The side AB of a triangle ABC is produced to a point D. The bisector of ACB cuts AB at E. Prove that < CAE + < CBD = 2 < CEB.

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None

In a class of 40 students, 25 speak Hausa, 16 speak Igbo, 21 speak Yoruba and each of the students speak at least one of the these three languages. If 8 speak Hausa and Igbo, 11 speak Hausa and Yoruba and 6 speak Igbo and Yoruba.

(a) Draw a Venn diagram to illustrate the information, using x to represent the number of students that speak all three languages.

(b) calculate the value of x.

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None

(a) ABCD is a trapezium in which AB // DC, |AB| = 8cm, < ABC = 60°, |BC| = 5.5cm and |BD| = 8.3cm. Using a ruler and a pair of compasses only, construct:

(i) the trapezium ABCD ; (ii) a rectangle PQCD, where P, Q are two points AB;

(b) Measure |AB| and |QB|.

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A carpenter was told to make a rectangular desk with top of dimension 50cm by 40cm. The carpenter actually made the desk 60cm by 35cm. 

(a) Calculate the percentage error in the (i) length and the breadth ; (ii) area of the table top.

(b) Find the product of the two errors in a(i).

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None

An aeroplane flies from a town P(lat. 40°N, 38°E) to another town Q(lat. 40°N, 22°W). It later flies to a third town T(28°N, 22°W). Calculate the :

(a) distance between P and Q along their parallel of latitude ;

(b) distance between Q and T along their line of longitudes;

(c) average speed at which the aeroplane will fly from P to T via Q, if the journey takes 12 hours, correct to 3 significant figures. [Take the radius of the earth = 6400km ; \(\pi = 3.142\)]

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The feet of two vertical poles of height 3m and 7m are in line with a point P on the ground, the smaller pole being between the taller pole and P and at a distance of 20m from P. The angle of elevation of the top (T) of the taller pole from the top (R) of the smaller pole is 30°. Calculate the :

(i) distance RT ; (ii) distance of the foot of the taller pole from P, correct to three significant figures ; (iii) angle of elevation of T from P, correct to one decimal place.

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