We have two prices for a notebook, the price today and yesterday:
[tex]\begin{gathered} P_{\text{today}}=3.5 \\ P_{\text{yesterday}}=3.75 \end{gathered}[/tex]We want to find in what percentage the price today decreased from yesterday price, so we compute:
[tex]\frac{P_{\text{today}}-P_{\text{yesterday}}}{P_{\text{yesterday}}}=\frac{3.5-3.75}{3.75}=-\frac{1}{15}\cong-0.06666_{}[/tex]Multiplying by 100% we find in how much percent the price decreased. We find that the price decreased by 6.7% percent.
