2007 - WAEC Mathematics Past Questions and Answers - page 1

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

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

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

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

\(\frac{3x^{3}}{(3x)^{3}}\
\frac{3x^{3}}{3x\times 3x\times 3x}=\frac{3\times x\times x\times x}{3\times 3\times 3\times x\times x\times x}=\frac{1}{9}\)

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

x + 3 = 0 => x = -3