The total purchase is unknown, but the subtotal is given as 23.99, while the tax rate is 5%. The total can be calculated as the portion of 100% after the deduction of 5% tax.
If the tax rate is 5%, which is 0.05 or 1/20, then the purchase price (23.99) is 95%, which is 0.95 or 19/20.
Therefore, to calculate the total purchase price, we use the following;
[tex]\begin{gathered} \frac{23.99}{x}=\frac{19}{20} \\ \text{Cross multiply and you now have;} \\ x=\frac{23.99(20)}{19} \\ x=\frac{479.8}{19} \\ x=25.2526\ldots \\ x\approx25.25 \end{gathered}[/tex]The total purchase price therefore is $25.25 (approximately) and the proportion used is 19/20.
