2008 - JAMB Mathematics Past Questions and Answers - page 9

(\frac{t + 2t - 1 + t - 2 + 2t - 1 + 4t + 2t + 2}{6})

= (\frac{12t - 2}{6})

= (\frac {12t}{6}) - (\frac{2}{6})

= 2t - (\frac{1}{3})

0, 0, 1, 1, 2, 4, 4, 4, 4

median = 2

Range = H - L

= 4x - (x - 1)

= 4x - x + 1

= 3x + 1

(\begin{array}{c|c} x & f & fx & x - \bar{x} & f(x - \bar{x}) \ \hline 2 & 1 & 2 & -3 & -3 & 3\ 4 & 1 & 4 & -1 & 1 & 1\ 5 & 1 & 5 & 0 & 0 & 0 \9 & 1 & 9 & 4 & 4 & 4 \ \hline & 4 & 20 & & & 8 \end{array})

x = (\frac{\sum fx}{\sum fx})

= (\frac{20}{4})

= 5

MD = (\frac{\sum f(x - \bar{x})}{\sum f})

= (\frac{8}{4})

= 2

Acceptance

(\frac{10!}{3!2!2!})

(^{10}C_{6})

(\frac{10!}{(n - r)!r!})

n = 10, r = 6

= (\frac{10!}{(10 - 6)!6!})

= (\frac{10!}{4!6!})

= (\frac{10 \times 9 \times 8 \times 7}{4 \times 3 \times 2 \times 1})

= 5 x 3 x 2 x 7

= 210

Obstruction

if a T is picked

p = (\frac{2}{11})

(\begin{array}{c|c}Number & 1 & 2 & 3 & 4 & 5 & 6 \ \hline Frequency & 12 & 18 & x & 30 & 2x & 45\end{array})

12 + 18 + x + 30 + 2x + 45 = 150

3x + 105 = 150

3x = 150 - 105

3x = 45

x = (\frac{45}{3})

x = 15

probability of 5 = (\frac{30}{150})

= (\frac{1}{5})

50 + 30 + y = 180

80 + y = 180

y = 100

180 + x = 180^o

x = 180^o - 100^o

x = 80^o

74 + x + x = 180

2x = 180 - 74

2x = 103

x = 53