In a class, the ratio of the number of girls to the number of boys is \(3 : 2\).
Calculate the percentage of the girls in the class.
The ratio of the number of girls to the total number of students is \(3:5=\dfrac{3}{5}\).
Thus, the percentage of the girls in the class is
\(\begin{aligned}\dfrac{3}{ 5}& =\dfrac{ 3 × 20}{ 5 × 20} \\\\&=\dfrac{60}{100} \\\\&=60\%. \end{aligned}\)
A box contains \(8\) ribbons.
Two of the ribbons are red.
What is the percentage of red ribbons in the box?
Let the percentage of red ribbons in the box be \(x\).
\(\begin{aligned} \dfrac{x}{100}&=\dfrac{\text{Number of red ribbons}}{\text{Total number of ribbons}} \\\\\dfrac{x}{100}&=\dfrac{2}{8} \\\\8\times x&=2\times100 \\\\x&=\dfrac{200}{8} \\\\&=25. \end{aligned}\)
Thus, the percentage of red ribbons in the box is \(25\%\).
Prepare exams with mock exam papers