WAEC Mathematics Past Questions & Answers - Page 88

T₁, T₂, T₃

2, -9, -20 .... -141

l = a + (n - 1)d

first term, a = 2

common difference d = T₃ - T₂

= T₂ - T₁

= -20 - (-9) = -9 -2

= -20 + 9

= -9 -2

= -20 + 9

= -11

-11 = -11

d = -1

last term l = -141

-141 = 2 + (\(\cap\) - 1) (-11)

-141 = 2 + (-11 \(\cap\) + 11)

= 2 - 11\(\cap\) + 11

-141 = 13 - 11\(\cap\)

-141 - 13 = -11\(\cap\)

-154 = -11\(\cap\)

\(\cap\) = \(\frac{-154}{-11}\)

\(\cap\) = 14

number of sides = \(\frac{360^o}{\theta} = \frac{360^o}{306o}\)

n = 12^o

Sum of interior angle = (n - 2) 180^o

(12 - 2) 180v = 10 x 180^o

= 1800^o

prob(p) = \(\frac{1}{5}\)

prob(Q) = \(\frac{1}{4}\)

Prob(neither p) = 1 - \(\frac{1}{5}\)

\(\frac{5 - 1}{5} = \frac{4}{5}\)

prob(neither Q) = 1 - \(\frac{1}{4}\)

\(\frac{4 - 1}{4} = \frac{3}{4}\)

prob(neither of them) = \(\frac{4}{5} \times \frac{3}{4} = \frac{12}{20}\)

= \(\frac{3}{5}\)

\(3 \sqrt{0.0005957}\)

\(\begin{array}{c|c} \log No(0.0005957) & \frac{1}{3} \log \frac{1}{3} \\ \hline (0.0005957)^{\frac{1}{3}} & 4.7750 \times \frac{1}{3} \\ & 6 + 2.7750 \\\hline & 3 \\\hline & 2.9250\end{array}\)

p = { 1, 2, 3}

Q = {2, 3, 5}

prob(prime number) = prob(1 and 2) or

= prob(2 and 3) or

= prob(3 and 2)

There are three possibilities of the sum being prime

Total possibility = 9

probability(sum being prime) = \(\frac{3}{9}\)

= \(\frac{1}{3}\)