21 - 30 of 49 Questions
# | Question | Ans |
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21. |
If x : y = 3 : 2 and y : z = 5 : 4, find the value of x in the ratio x : y : z A. 8 B. 10 C. 15 D. 20 |
C |
22. |
Given that cos x = \(\frac{12}{13}\), evaluate \(\frac{1 - \tan x}{\tan x}\) A. \(\frac{5}{13}\) B. \(\frac{5}{7}\) C. \(\frac{7}{5}\) D. \(\frac{13}{5}\) Detailed Solutioncos x\(\frac{12}{13}\)132 = 122 + a2 169 = 144 + a2 a2 = 169 - 144 a2 = 25 a \(\sqrt{25}\) a = 5 tan x = \(\frac{5}{12}\) \(\frac{1 - \tan x}{\tan x} = \frac{1 - \frac{5}{12}}{\frac{5}{12}}\) \(\frac{\frac{1 - \frac{5}{12}}{12 - 5}}{12} = \frac{\frac{7}{12}}{\frac{5}{12}}\) = \(\frac{7}{2} \div \frac{5}{12}\) = \(\frac{7}{12} \times \frac{12}{5} = \frac{7}{5}\) |
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23. |
Approximate 0.0033780 to 3 significant figures A. 338 B. 0.338 C. 0.00338 D. 0.003 |
C |
24. |
Simplify \(\frac{\sqrt{8^2 \times 4^{n + 1}}}{2^{2n} \times 16}\) A. 16 B. 8 C. 4 D. 1 Detailed Solution\(\frac{\sqrt{8^2 \times 4^{n + 1}}}{2^{2n} \times 16}\)= \(\frac{\sqrt{2^{3(2)} \times 2^{2(n + 1)}}}{2^{2n} \times 2^4}\) = \(\frac{\sqrt{2^6 \times 2^{2n + 2)}}}{2^{2n} + 4}\) = \(\frac{\sqrt{2^6 + 2^{2n + 2)}}}{2^{2n} + 4}\) = \(\frac{\sqrt{2^{2n + 8}}}{2^{2n} + 4}\) = \(\sqrt{2^{2n + 8} \div 2^{2n} + 4}\) = \(\sqrt{2^{2n - 2n} + 8 - 4}\) = \(\sqrt{2^4}\) = \(\sqrt{16}\) = 4 |
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25. |
If \(\frac{2}{x - 3} - \frac{3}{x - 2}\) is equal to \(\frac{p}{(x - 3)(x - 2)}\), find p A. -x - 5 B. -(x + 3) C. 5x - 13 D. 5 - x Detailed Solution\(\frac{2}{x - 3} - \frac{3}{x - 2}\) = \(\frac{p}{(x - 3)(x - 2)}\)\(\frac{2(x - 2) - 3(x - 3)}{(x - 3)(x - 2)}\) = \(\frac{p}{(x - 3)(x - 2)}\) = \(\frac{2x - 4 - 3x + 9}{(x - 3)(x - 2)}\) = \(\frac{p}{(x - 3)(x - 2)}\) \(\frac{-x + 5}{(x - 3)(x - 2)} = \frac{p}{(x - 3)(x - 2)}\) p(x - 3)(x - 2) = -x + 5(x - 3)(x - 2) p = -x + 5 or p = 5 - x |
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26. |
Subtract \(\frac{1}{2}\)(a - b - c) from the sum of \(\frac{1}{2}\)(a - b + c) and \(\frac{1}{2}\) A. \(\frac{1}{2}\) (a + b + c) B. \(\frac{1}{2}\) (a - b - c) C. \(\frac{1}{2}\) (a - b + c) D. \(\frac{1}{2}\) (a + b - c) Detailed Solution\(\frac{1}{2}\)(a - b + c) + \(\frac{1}{2}\)(a + b - c) - [\(\frac{1}{2}\) (a - b - c)]\(\frac{1}{2}a - \frac{1}{2}b + \frac{1}{2}c + \frac{1}{2}a + \frac{1}{2}b - \frac{1}{2}c - \frac{1}{2}a + \frac{1}{2}b + \frac{1}{2}c\) = \(\frac{1}{2}a + \frac{1}{2}b + \frac{1}{2}c\) = \(\frac{1}{2}(a + b + c)\) |
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27. |
A man's eye level is 1.7m above the horizontal ground and 13m from a vertical pole. If the pole is 8.3m high, calculate, correct to the nearest degree, the angle of elevation of the top of the pole from his eyes. A. 33o B. 32o C. 27o D. 26o Detailed Solutiontan \(\theta = \frac{opp}{adj} = \frac{6.6}{13}\)tan \(\theta = 0.5077\) \(\theta\) = tan-1 0.5077 \(\theta = 27^o\) |
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28. |
A chord subtends an angle of 120o at the centre of a circle of radius 3.5cm. Find the perimeter of the minor sector containing the chord, [Take \(\pi = \frac{22}{7}\)] A. 14\(\frac{1}{3}\)cm B. 12\(\frac{5}{6}\)cm C. 8\(\frac{1}{7}\)cm D. 7\(\frac{1}{3}\)cm Detailed Solutionperimeter of minor sector2r + \(\frac{\theta}{360} \times 2 \pi r\) = 2 x 3.5 + \(\frac{120^o}{360^o} \times 2 \frac{22}{7} \times 3.5\) = 7 + \(\frac{154}{21}\) = 7 + 7.33 = 14.33 = 14\(\frac{1}{3}\)cm |
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29. |
In parallelogram PQRS, QR is produced to M such that |QR| = |RM|. What fraction of the area of PQMS is the area of PRMS? A. \(\frac{1}{4}\) B. \(\frac{1}{3}\) C. \(\frac{2}{3}\) D. \(\frac{3}{4}\) Detailed SolutionThere are 3 triangles: \(\bigtriangleup\)MRS, \(\bigtriangleup\) and \(\bigtriangleup\) PRQArea PRMS has 2 triangles: \(\bigtriangleup\) MRS and \(\bigtriangleup\) RSP the fraction = \(\frac{2}{3}\) |
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30. |
In a cumulative frequency graph, the lower quartile is 18 years while the 60th percentile is 48 years. What percentage of the distribution is at most 18 years or greater than 48 years? A. 15% B. 35% C. 65% D. 85% |
C |
21. |
If x : y = 3 : 2 and y : z = 5 : 4, find the value of x in the ratio x : y : z A. 8 B. 10 C. 15 D. 20 |
C |
22. |
Given that cos x = \(\frac{12}{13}\), evaluate \(\frac{1 - \tan x}{\tan x}\) A. \(\frac{5}{13}\) B. \(\frac{5}{7}\) C. \(\frac{7}{5}\) D. \(\frac{13}{5}\) Detailed Solutioncos x\(\frac{12}{13}\)132 = 122 + a2 169 = 144 + a2 a2 = 169 - 144 a2 = 25 a \(\sqrt{25}\) a = 5 tan x = \(\frac{5}{12}\) \(\frac{1 - \tan x}{\tan x} = \frac{1 - \frac{5}{12}}{\frac{5}{12}}\) \(\frac{\frac{1 - \frac{5}{12}}{12 - 5}}{12} = \frac{\frac{7}{12}}{\frac{5}{12}}\) = \(\frac{7}{2} \div \frac{5}{12}\) = \(\frac{7}{12} \times \frac{12}{5} = \frac{7}{5}\) |
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23. |
Approximate 0.0033780 to 3 significant figures A. 338 B. 0.338 C. 0.00338 D. 0.003 |
C |
24. |
Simplify \(\frac{\sqrt{8^2 \times 4^{n + 1}}}{2^{2n} \times 16}\) A. 16 B. 8 C. 4 D. 1 Detailed Solution\(\frac{\sqrt{8^2 \times 4^{n + 1}}}{2^{2n} \times 16}\)= \(\frac{\sqrt{2^{3(2)} \times 2^{2(n + 1)}}}{2^{2n} \times 2^4}\) = \(\frac{\sqrt{2^6 \times 2^{2n + 2)}}}{2^{2n} + 4}\) = \(\frac{\sqrt{2^6 + 2^{2n + 2)}}}{2^{2n} + 4}\) = \(\frac{\sqrt{2^{2n + 8}}}{2^{2n} + 4}\) = \(\sqrt{2^{2n + 8} \div 2^{2n} + 4}\) = \(\sqrt{2^{2n - 2n} + 8 - 4}\) = \(\sqrt{2^4}\) = \(\sqrt{16}\) = 4 |
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25. |
If \(\frac{2}{x - 3} - \frac{3}{x - 2}\) is equal to \(\frac{p}{(x - 3)(x - 2)}\), find p A. -x - 5 B. -(x + 3) C. 5x - 13 D. 5 - x Detailed Solution\(\frac{2}{x - 3} - \frac{3}{x - 2}\) = \(\frac{p}{(x - 3)(x - 2)}\)\(\frac{2(x - 2) - 3(x - 3)}{(x - 3)(x - 2)}\) = \(\frac{p}{(x - 3)(x - 2)}\) = \(\frac{2x - 4 - 3x + 9}{(x - 3)(x - 2)}\) = \(\frac{p}{(x - 3)(x - 2)}\) \(\frac{-x + 5}{(x - 3)(x - 2)} = \frac{p}{(x - 3)(x - 2)}\) p(x - 3)(x - 2) = -x + 5(x - 3)(x - 2) p = -x + 5 or p = 5 - x |
26. |
Subtract \(\frac{1}{2}\)(a - b - c) from the sum of \(\frac{1}{2}\)(a - b + c) and \(\frac{1}{2}\) A. \(\frac{1}{2}\) (a + b + c) B. \(\frac{1}{2}\) (a - b - c) C. \(\frac{1}{2}\) (a - b + c) D. \(\frac{1}{2}\) (a + b - c) Detailed Solution\(\frac{1}{2}\)(a - b + c) + \(\frac{1}{2}\)(a + b - c) - [\(\frac{1}{2}\) (a - b - c)]\(\frac{1}{2}a - \frac{1}{2}b + \frac{1}{2}c + \frac{1}{2}a + \frac{1}{2}b - \frac{1}{2}c - \frac{1}{2}a + \frac{1}{2}b + \frac{1}{2}c\) = \(\frac{1}{2}a + \frac{1}{2}b + \frac{1}{2}c\) = \(\frac{1}{2}(a + b + c)\) |
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27. |
A man's eye level is 1.7m above the horizontal ground and 13m from a vertical pole. If the pole is 8.3m high, calculate, correct to the nearest degree, the angle of elevation of the top of the pole from his eyes. A. 33o B. 32o C. 27o D. 26o Detailed Solutiontan \(\theta = \frac{opp}{adj} = \frac{6.6}{13}\)tan \(\theta = 0.5077\) \(\theta\) = tan-1 0.5077 \(\theta = 27^o\) |
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28. |
A chord subtends an angle of 120o at the centre of a circle of radius 3.5cm. Find the perimeter of the minor sector containing the chord, [Take \(\pi = \frac{22}{7}\)] A. 14\(\frac{1}{3}\)cm B. 12\(\frac{5}{6}\)cm C. 8\(\frac{1}{7}\)cm D. 7\(\frac{1}{3}\)cm Detailed Solutionperimeter of minor sector2r + \(\frac{\theta}{360} \times 2 \pi r\) = 2 x 3.5 + \(\frac{120^o}{360^o} \times 2 \frac{22}{7} \times 3.5\) = 7 + \(\frac{154}{21}\) = 7 + 7.33 = 14.33 = 14\(\frac{1}{3}\)cm |
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29. |
In parallelogram PQRS, QR is produced to M such that |QR| = |RM|. What fraction of the area of PQMS is the area of PRMS? A. \(\frac{1}{4}\) B. \(\frac{1}{3}\) C. \(\frac{2}{3}\) D. \(\frac{3}{4}\) Detailed SolutionThere are 3 triangles: \(\bigtriangleup\)MRS, \(\bigtriangleup\) and \(\bigtriangleup\) PRQArea PRMS has 2 triangles: \(\bigtriangleup\) MRS and \(\bigtriangleup\) RSP the fraction = \(\frac{2}{3}\) |
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30. |
In a cumulative frequency graph, the lower quartile is 18 years while the 60th percentile is 48 years. What percentage of the distribution is at most 18 years or greater than 48 years? A. 15% B. 35% C. 65% D. 85% |
C |