Question

The cost of a DVD box set increase from 30 to 35 a student says that this represent a 5% increase in the price explain the students error what is the actual percent increase

Answer 1

so it went from 30 to 35, or 5 bucks, if we take 30 to be the 100%, what is 5 off of it in percentage?


`\bf \begin{array}{ccll} amount&\%\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 30&100\\ 5&p \end{array}\implies \cfrac{30}{5}=\cfrac{100}{p}\implies p=\cfrac{5\cdot 100}{30}`