Question

Greg practiced playing his clarinet for 12 minutes He has practiced 40% of the amount of time he needs to practice today how many more minutes does Greg need to practice today?

Answer 1

he already practiced 40%, he needs to do the rest, the remaining 60%.

now, we know that 40% is 12 minutes, what is the 60% anyway?


`\bf \begin{array}{ccll} amount&\%\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 12&40\\ x&60 \end{array}\implies \cfrac{12}{x}=\cfrac{40}{60}\implies \cfrac{12\cdot 60}{40}=x`

he needs to practice an extra "x" minutes.