1 Answer

Duval · Answer 1 · 2023-07-18T19:46:23+0000

Hello!

To solve exercise 9, we must use the rule of three.

Note that the initial price was R12 (corresponds to 100%).

The new price is R10.8 (we'll consider x%).

Using the rule of three, we will have:

$\begin{gathered} (12\rightarrow100\%)/(10.8\rightarrow x\%) \\ \\ 12\cdot x=10.8\cdot100 \\ 12x=1080 \\ x=(1080)/(12) \\ \\ x=90\% \end{gathered}$

Now, let's calculate the difference between the initial percentage and the new percentage:

$100\%-90\%=10\%\text{ of decrease}$

Answer:

10% of decrease.