\begin{testbox} \begin{questions} \question[6] Express each percentage as a fraction in its simplest form. \begin{parts}\begin{multicols}{2} \part \(18 \%\) \begin{solutionordottedlines}[1cm] $\frac{18}{100} = \frac{9}{50}$ \end{solutionordottedlines} \part \(64 \%\) \begin{solutionordottedlines}[1cm] $\frac{64}{100} = \frac{16}{25}$ \end{solutionordottedlines} \part \(2.6 \%\) \begin{solutionordottedlines}[1cm] $\frac{2.6}{100} = \frac{26}{1000} = \frac{13}{500}$ \end{solutionordottedlines} \part \(8.5 \%\) \begin{solutionordottedlines}[1cm] $\frac{8.5}{100} = \frac{85}{1000} = \frac{17}{200}$ \end{solutionordottedlines} \part \(37 \frac{1}{2} \%\) \begin{solutionordottedlines}[1cm] $37.5\% = \frac{37.5}{100} = \frac{375}{1000} = \frac{3}{8}$ \end{solutionordottedlines} \part \(6 \frac{2}{3} \%\) \begin{solutionordottedlines}[1cm] $6\frac{2}{3}\% = \frac{20}{3} \times \frac{1}{100} = \frac{20}{300} = \frac{2}{30} = \frac{1}{15}$ \end{solutionordottedlines} \end{multicols}\end{parts} \question[6] Express each percentage as a decimal. \begin{parts}\begin{multicols}{2} \part \(8 \%\) \begin{solutionordottedlines}[1cm] $0.08$ \end{solutionordottedlines} \part \(27 \%\) \begin{solutionordottedlines}[1cm] $0.27$ \end{solutionordottedlines} \part \(9.6 \%\) \begin{solutionordottedlines}[1cm] $0.096$ \end{solutionordottedlines} \part \(45.8 \%\) \begin{solutionordottedlines}[1cm] $0.458$ \end{solutionordottedlines} \part \(12 \frac{1}{4} \%\) \begin{solutionordottedlines}[1cm] $12.25\% = 0.1225$ \end{solutionordottedlines} \part \(38 \frac{1}{2} \%\) \begin{solutionordottedlines}[1cm] $38.5\% = 0.385$ \end{solutionordottedlines} \end{multicols}\end{parts} \question[6] Express each rational number as a percentage. \begin{parts}\begin{multicols}{2} \part \(\frac{2}{5}\) \begin{solutionordottedlines}[1cm] $\frac{2}{5} = 0.4 = 40\%$ \end{solutionordottedlines} \part \(\frac{5}{8}\) \begin{solutionordottedlines}[1cm] $\frac{5}{8} = 0.625 = 62.5\%$ \end{solutionordottedlines} \part 0.61 \begin{solutionordottedlines}[1cm] $0.61 = 61\%$ \end{solutionordottedlines} \part 0.02 \begin{solutionordottedlines}[1cm] $0.02 = 2\%$ \end{solutionordottedlines} \part \(\frac{4}{7}\) \begin{solutionordottedlines}[1cm] $\frac{4}{7} \approx 0.5714 = 57.14\%$ \end{solutionordottedlines} \part \(\frac{5}{9}\) \begin{solutionordottedlines}[1cm] $\frac{5}{9} \approx 0.5556 = 55.56\%$ \end{solutionordottedlines} \end{multicols}\end{parts} \question[12] Complete the following table. \begin{center} \begin{tabular}{|c|c|c|c|} \hline & Percentage & Fraction & Decimal \\ \hline a & 25\% & $\frac{1}{4}$ & 0.25 \\ \hline b & 30\% & $\frac{3}{10}$ & 0.3 \\ \hline c & 26\% & $\frac{13}{50}$ & 0.26 \\ \hline d & 66.67\% & $\frac{2}{3}$ & 0.6667 \\ \hline e & 8\% & $\frac{2}{25}$ & 0.08 \\ \hline f & 7.5\% & $\frac{3}{40}$ & 0.075 \\ \hline \end{tabular} \end{center} \question[4] Calculate: \begin{parts} \part \(8 \%\) of 120 \begin{solutionordottedlines}[1cm] $120 \times 0.08 = 9.6$ \end{solutionordottedlines} \part \(16 \%\) of 54 \begin{solutionordottedlines}[1cm] $54 \times 0.16 = 8.64$ \end{solutionordottedlines} \part \(85 \%\) of \(\$ 400\) \begin{solutionordottedlines}[1cm] $400 \times 0.85 = \$340$ \end{solutionordottedlines} \part \(9 \frac{1}{2} \%\) of \(\$ 6000\) \begin{solutionordottedlines}[1cm] $6000 \times 0.095 = \$570$ \end{solutionordottedlines} \end{parts} \question[2] There are 650 students at a high school, \(54 \%\) of whom are boys. How many boys are at the school? \begin{solutionordottedlines}[1in] $650 \times 0.54 = 351$ \end{solutionordottedlines} \question[2] Netball is played by \(6 \%\) of Australians. If the population of Australia is 22500000 , how many Australians play netball? \begin{solutionordottedlines}[1in] $22500000 \times 0.06 = 1350000$ \end{solutionordottedlines} \question[2] In a class of 25 students, 8 travel to school by train. What percentage of the class travel to school by train? \begin{solutionordottedlines}[1in] $\frac{8}{25} = 0.32 = 32\%$ \end{solutionordottedlines} \question[2] In a survey of 1200 adults, it was discovered that 114 of them were unemployed. What percentage of the adults surveyed were unemployed? \begin{solutionordottedlines}[1in] $\frac{114}{1200} = 0.095 = 9.5\%$ \end{solutionordottedlines} \question[4] Find the new value if: \begin{parts}\begin{multicols}{2} \part 80 is increased by \(40 \%\) \begin{solutionordottedlines}[1cm] $80 \times 1.40 = 112$ \end{solutionordottedlines} \part 150 is increased by \(6 \%\) \begin{solutionordottedlines}[1cm] $150 \times 1.06 = 159$ \end{solutionordottedlines} \part 240 is decreased by \(12 \%\) \begin{solutionordottedlines}[1cm] $240 \times 0.88 = 211.2$ \end{solutionordottedlines} \part 160 is decreased by \(4 \%\) \begin{solutionordottedlines}[1cm] $160 \times 0.96 = 153.6$ \end{solutionordottedlines} \end{multicols}\end{parts} \question[2] During a sale, the price of a sofa bed is reduced by \(20 \%\). If the original price of the bed was \(\$ 650\), what is its sale price? \begin{solutionordottedlines}[1in] $650 \times 0.80 = \$520$ \end{solutionordottedlines} \question[2] A salesperson is given a salary increase of \(4 \%\). If her existing weekly salary is \(\$ 640\), what will her new weekly salary be? \begin{solutionordottedlines}[1in] $640 \times 1.04 = \$665.60$ \end{solutionordottedlines} \question[2] Joe's Electrical Store is having an \(8 \%\) discount sale. The sale price of some items is given below. Calculate the price of the items before they were reduced. \begin{solutionordottedlines}[1in] \end{solutionordottedlines} \begin{parts} \part Heater \(\$ 276\) \begin{solutionordottedlines}[1cm] $276 \div 0.92 = \$300$ \end{solutionordottedlines} \part Vacuum cleaner \(\$ 138\) \begin{solutionordottedlines}[1cm] $138 \div 0.92 = \$150$ \end{solutionordottedlines} \part Dishwasher \(\$ 690\) \begin{solutionordottedlines}[1cm] $690 \div 0.92 = \$750$ \end{solutionordottedlines} \part Microwave \(\$ 132.80\) \begin{solutionordottedlines}[1cm] $132.80 \div 0.92 = \$144.35$ \end{solutionordottedlines} \end{parts} \question[2] The enrolment of a school increased from 680 to 740 . Calculate the percentage increase, correct to 2 decimal places. \begin{solutionordottedlines}[1in] $\frac{740 - 680}{680} \times 100 \approx 8.82\%$ \end{solutionordottedlines} \question[2] During a sale the price of a suit is reduced from \(\$ 420\) to \(\$ 370\). Calculate the percentage discount, correct to 1 decimal place. \begin{solutionordottedlines}[1in] $\frac{420 - 370}{420} \times 100 \approx 11.9\%$ \end{solutionordottedlines} \question[4] What single percentage change, correct to 2 decimal places, is equivalent to each of these multiple changes? \begin{parts} \part A \(6 \%\) increase followed by a \(12 \%\) increase \begin{solutionordottedlines}[1cm] $1.06 \times 1.12 = 1.1872 \approx 18.72\%$ increase \end{solutionordottedlines} \part A \(10 \%\) increase followed by a \(10 \%\) decrease \begin{solutionordottedlines}[1cm] $1.10 \times 0.90 = 0.99 = 1\%$ decrease \end{solutionordottedlines} \part A \(16 \%\) decrease followed by a \(8 \%\) decrease \begin{solutionordottedlines}[1cm] $0.84 \times 0.92 = 0.7728 \approx 22.72\%$ decrease \end{solutionordottedlines} \part A \(12 \%\) decrease followed by a \(14 \%\) increase \begin{solutionordottedlines}[1cm] $0.88 \times 1.14 = 1.0032 \approx 0.32\%$ increase \end{solutionordottedlines} \end{parts} \question[2] Over the course of a year an employee is given successive salary increases of \(4 \%, 6 \%\) and 5\%. \begin{solutionordottedlines}[1in] \end{solutionordottedlines} \begin{parts} \part If the employee's original monthly salary was \(\$ 2600\), what is the employee's salary after the three increases? \begin{solutionordottedlines}[2cm] $2600 \times 1.04 \times 1.06 \times 1.05 = \$3038.28$ \end{solutionordottedlines} \part What single percentage change is equivalent to the three successive salary increases? \begin{solutionordottedlines}[2cm] $1.04 \times 1.06 \times 1.05 = 1.1688 \approx 16.88\%$ increase \end{solutionordottedlines} \end{parts} \question[2] To obtain a bonus, a salesperson's sales must increase by \(20 \%\) in a two-month period. If the salesperson's sales increase by \(8 \%\) in the first month, by what percentage must they increase in the second month to ensure the bonus is obtained? \begin{solutionordottedlines}[2cm] Let $x$ be the required percentage increase for the second month. $1.08 \times (1 + \frac{x}{100}) = 1.20$ $1 + \frac{x}{100} = \frac{1.20}{1.08}$ $\frac{x}{100} = \frac{1.20}{1.08} - 1$ $x = (1.1111 - 1) \times 100$ $x \approx 11.11\%$ \end{solutionordottedlines} \question[2] Mia invests \(\$ 6000\) in the bank. How much will she have in her account after three years if the bank pays: \begin{parts} \part \(8 \%\) simple interest p.a. \begin{solutionordottedlines}[2cm] $6000 + (6000 \times 0.08 \times 3) = 6000 + 1440 = \$7440$ \end{solutionordottedlines} \part \(4 \%\) compound interest p.a. \begin{solutionordottedlines}[2cm] $6000 \times (1 + 0.04)^3 \approx 6000 \times 1.124864 = \$6749.18$ \end{solutionordottedlines} \end{parts} \question[3] The value of a new car depreciates at a compound rate of \(6 \%\) each year. If the car has an initial value of \(\$ 19960\), calculate its value after: \begin{parts} \part one year \begin{solutionordottedlines}[2cm] $19960 \times (1 - 0.06) = 19960 \times 0.94 = \$18762.40$ \end{solutionordottedlines} \part five years \begin{solutionordottedlines}[2cm] $19960 \times (1 - 0.06)^5 \approx 19960 \times 0.747258 = \$14920.47$ \end{solutionordottedlines} \part 10 years \begin{solutionordottedlines}[2cm] $19960 \times (1 - 0.06)^{10} \approx 19960 \times 0.558395 = \$11145.89$ \end{solutionordottedlines} \end{parts} \end{questions} \end{testbox}