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No expanded working has been attached for this question yet. The verified answer is Option B.

No expanded working has been attached for this question yet. The verified answer is Option D.

The dissolution of sugar in tea is accompanied by positive change in entropy. When there is a change in the state of a substance from solid to liquid, there is an increase in entropy. In general, if a substance changes its structure from a condensed state to a less condensed state, then we say there is an increase in entropy.

Percentage birthrate = \(\frac{62}{6250} \times 100%\) = \(\frac{6200}{6250}\) = 0.992% \(\approx\) 1.0%.

1¼ ÷ [ 2 ÷ ¼] of 28 Apply BODMAS rules \( \frac{5}{4}\) ÷ [ 2 ÷ ¼ × 28 ] \( \frac{5}{4} ÷ \frac{2}{7} \) \( \frac{5}{4} × \frac{7}{2} \) \( \frac{35}{8}\) = \(4 \frac{3}{8}\)

\( x^2 + 9x + 20 \) Find the two numbers whose product is 20 and its sum is 9} \( 5x \times 4x = 20x^2\) \(5x + 4x = 9x\) \((x^2 + 5x) + (4x + 20)\) \( x(x + 5)+ 4(x + 5) = (x + 5)(x + 4)\)

Total of their ages: 18 + 20 + 22 = 60 The second staff will get \(\frac{20}{60} \times 120,000\) = N40,000.00K

n(X ∪ Y) = n(X) + n(Y) − n(X ∩ Y) = 15 + 12 − 7 ∴ n(X ∪ Y) = 20

Starting from 3x − z \(\leq\) 9 x = 0, substitute the value of x (i.e. x = 0) into the equation 3x − z \(\leq\) 9 3(0) − z \(\leq\) 9 z \(\leq\) − 9 If z = 0 Then, 3x − 0 \(\leq\) 9 3x \(\leq\) 9 x \(\leq\) 3 Intercept of x and z i.e (x,z) = (3, -9)

log101.5 + 3 log102 − log100.3 log101.5 + log1023 − log100.3 [log10(1.5 × 23) ÷ log100.3] [log10(15/10 × 8 ) ÷ log10( 3/10)] log10(15/10 × 8 × 10/3 ) log1040

The total surface area of a cylinder = 2\pirl + 2\pir2 = 2\pir(l + r) = 2 \times 3.14 x 5(7+5) 2 \times 3.14 \times 12 x 5 = 377.1cm (1DP)

Given: \(x + y = 90^\circ ... (1)\) \((\sin x + \sin y)^{2} - 2\sin x \sin y = \sin^{2} x + \sin^{2} y + 2\sin x \sin y - 2\sin x \sin y\) = \(\sin^{2} x + \sin^{2} y ... (2)\) Recall: \(\sin x = \cos (90 - x) ... (a)\) From (1), \(y = 90 - x ... (b)\) Putting (a) and (b) in (2), we have \(\sin^{2} x + \sin^{2} y \equiv \cos^{2} (90 - x) + \sin^{2} (90 - x)\) = 1

His annual salary = N2000 His allowances = N600 So his taxable income = Annual salary − allowance = N2000 − N600 = N1400 He pay at 5% Then, his allowance income tax 5/100 \times 1400 = N70

Using the quadratic formula, we have \(x = \frac{-b \pm \sqrt{b^{2} - 4ac}}{2a}\) From the equation \(3x^{2} - 4x - 5 = 0\), a = 3, b = -4 and c = -5. \(\therefore x = \frac{-(-4) \pm \sqrt{(-4)^{2} - 4(3)(-5)}}{2(3)}\) = \(\frac{4 \pm \sqrt{16 + 60}}{6}\) = \(\frac{4 \pm \sqrt{76}}{6}\) = \(\frac{4 \pm 8.72}{6}\) = \(\frac{4 + 8.72}{6} \text{ or } \frac{4 - 8.72}{6}\) = \(\frac{12.72}{6} \text{ or } \frac{-4.72}{6}\) \(x = \text{2.12 or -0.79}\)

nth term of a linear sequence (AP) = a+(n − 1)d first term = 6, last term = 10 sum − 40 i.e. a = 6, l = 10, S = 40 \(S_n\)= n/2(2a + (n − 1)d or Sn = \div2 (a + l) \(S_n\) = n/2(a + l) 40 = n/2(6 + 10) 40 = 8n 8n = 40 8n = 40 n = 40/8 = 5 The number of terms = 5