2006 - WAEC Mathematics Past Questions and Answers - page 1

(0.13)(^3) = 0.13 x 0.13 x 0.13 = 0.002197

= 0.00220 (3 s.f)

11011${}_2$ - 1101${}_2$ = 1110${}_2$

(\frac{25 \frac{2}{3} \div 25 \frac{1}{6}}{( \frac{1}{5})^{-\frac{7}{6}} \times ( \frac{1}{5})^{\frac{1}{6}}}) = (\frac{25^{4 - \frac{1}{6}}}{(\frac{1}{5})^{-7 + \frac{1}{6}}})

= (\frac{25^{\frac{1}{2}}}{(\frac{1}{5})^{-1}})

= (\frac{(5^2)^{\frac{1}{2}}}{(5^{-1})^{-1}})

= (\frac{5}{5})

= 1

(\frac{x - 4}{4} - \frac{x - 3}{6}) = (\frac{3(x - 4) - 2(x - 3)}{12})

= (\frac{3x -12 - 2x + 6}{12})

= (\frac{3x - 2x - 12 + 6}{12})

= (\frac{x - 6}{12})

for undefined expression, the denomination is zero 4x - 3 = 0

4x = 3; x = (\frac{3}{4})

Pr(head) = (\frac{1}{2}), Pr(tail) = (\frac{1}{2}):Pr(2 heads)

= (\frac{1}{2}) x (\frac{1}{2}) = (\frac{1}{4})

Pr(2 heads and tail) 3 times

= ((\frac{1}{4}) x (\frac{1}{2})) x 3

= (\frac{3}{8})

If 30% of y = x, then 30% of 3y = 3x

(\frac{40}{100} \times 50)kg = 20kg

(\frac{1}{8}) of 20kg for cake; (\frac{1}{8}) x (\frac{20}{1})

= 2(\frac{1}{2})kg

tan y = 0.404; y = tan^-1 0.0404(tables);y = 22^o

cos 2y = cos 2(22^o); cos 44^o

= 0.719