2000 - WAEC Mathematics Past Questions and Answers - page 1
\(\frac{7}{19}\times \frac{100}{1}\% = 36.8\%\)
Express 398753 correct to three significant figures
\frac{10\times \sqrt{2}}{4\sqrt{2}\times\sqrt{2}}=\frac{10\sqrt{2}}{4\times 2}= \frac{5}{4}\sqrt{2}\)
Find the missing number in the addition of the following numbers, in base seven
\(\begin{matrix}
4 & 3 & 2 & 1\
1 & 2 & 3 & 4\
* & * & * & *\
1&2&3&4&1
\end{matrix}\)
4321\(_7\) + 1234\(_7\) = 5555\(_7\)
Missing number = 12341\(_7\) - 5555\(_7\)
= 3453\(_7\)
What fraction must be subtracted from the sum of \(2\frac{1}{6}\) and \(2\frac{7}{12}\) to give \(3\frac{1}{4}\)?
\(2\frac{1}{6} + 2\frac{7}{12}\)
= \(\frac{13}{6} + \frac{31}{12}\)
= \(\frac{26 + 31}{12}\)
= \(\frac{57}{12} = \frac{19}{4}\)
\(\frac{19}{4} - 3\frac{1}{4}\)
= \(\frac{19}{4} - \frac{13}{4}\)
= \(\frac{6}{4}\)
= \(1\frac{1}{2}\)
\frac{1}{\left(\sqrt[4]{\frac{16}{81}}\right)^3}\times \frac{10}{9}=\frac{1}{\left(\frac{2}{3}\right)^3}\times\frac{10}{9}\
=\frac{27}{8}\times \frac{10}{9}=\frac{15}{4}\)
If \(104_x = 68\), find the value of x
\(104_x = 68\
1 \times x^2 + 0 \times x + 4 \times x^0 = 68\
x^2 = 68 - 4; x^2 = 64\
x = \sqrt{64}=8\)
The ages of three men are in the ratio 3:4:5. If the difference between the ages of the oldest and youngest is 18 years, find the sum of the ages of the three men
Given that the ages are in the ratio 3: 4: 5.
Let the sum of their ages be t.
\(\therefore\) The youngest age = \(\frac{3}{12} t\)
The eldest age = \(\frac{5}{12} t\)
\(\implies \frac{5}{12} t - \frac{3}{12} t = 18\)
\(\frac{2t}{12} = 18 \implies t = \frac{18 \times 12}{2}\)
t = 108 years.
The sum of their ages = 108 years.
Given that \(log_4 x = -3\), find x.