2007 - WAEC Mathematics Past Questions and Answers - page 1

((111_{two})^{2}=(111_{two})(111_{two})<br /> =1 \times 2^{2}+1\times2^{1}+1\times 2^{0}=4+2+1=7_{{ten}}<br /> (111{two})^{2}=7\times 7=49<br /> \begin{matrix}
2 & 49\
2 & 24\hspace{1mm}R\hspace{1mm}1\
2 & 12\hspace{1mm}R\hspace{1mm}0\
2 & 6\hspace{1mm}R\hspace{1mm}0\
2 & 3\hspace{1mm}R\hspace{1mm}0\
2 & 1\hspace{1mm}R\hspace{1mm}1\
& 0\hspace{1mm}R\hspace{1mm}1\hspace{1mm}\uparrow
\end{matrix} <br /> =110001_{2})

((0.3\times 10^{5})\div (0.4\times 10^{7})<br /> \frac{3}{10}\times 10^{5}\div \frac{4}{10}\times 10^{7}=3\times 10^{4}\div 4\times 10^{6}<br /> \frac{3\times 10^{4}}{4\times 10^{7}}=\frac{3}{4}\times 10^{-2}=0.75\times 10^{-2}<br /> 7.5\times 10^{-3})

(p\propto \frac{1}{q} = q \propto \frac{1}{p})

(3\sqrt{45}-12\sqrt{5}+16\sqrt{20}<br /> 3\sqrt{5\times 9}-12\sqrt{5}+16\sqrt{4\times 5}<br /> 3\times 3\sqrt{5}-12\sqrt{5}+16\times 2\sqrt{5}<br /> 9\sqrt{5}-12\sqrt{5}+32\sqrt{5}<br /> 29\sqrt{5})

(\frac{3x^{3}}{(3x)^{3}}<br /> \frac{3x^{3}}{3x\times 3x\times 3x}=\frac{3\times x\times x\times x}{3\times 3\times 3\times x\times x\times x}=\frac{1}{9})

(Abu = 2x<br /> Kayode = x<br /> Uche = \frac{x}{2}<br /> 2x+x+\frac{x}{2}=140,000<br /> \frac{7x}{2}=140,000<br /> 7x = 280,000<br /> x=\frac{280,000}{7}<br /> x=40,000)Kayode receives N40,000

x + 3 = 0 => x = -3