30% off the prices means that the there is a discount of 30% on the original price.
If 30% discount is given, then it means that the new cost price will be = 100% -30% the original price
=> 70% the original price
Since the Electric Guitar was sold at $315
Then it means that 70% the original price = $315
Let the original price be P
then 70% of P = $315
[tex]\begin{gathered} 70percent=\frac{70}{100}\text{ = 0.7} \\ \end{gathered}[/tex]70% of P = 0.7 x P = 0.7P
Question A.
We can then obtain P, the original price by equatin to $315
=> 0.7P = $315
To get P, divide both sides by the coefficient of P
[tex]\frac{0.7p}{0.7}=\frac{315}{0.7}[/tex]P = $450
Orignal Price of Guitar = $450
Question B
Amount saved = Original Price - Selling Price
Amount saved = $450 -$315
=> Amount saved = $135
