First, we need to calculate the total cost of the iPhone and it is calculated as:
[tex]\text{Total Cost}=\text{Initial cost + (Initial Cost)}\cdot(\text{ tax rate)}[/tex]
So, replacing the initial cost by $899 and the tax rate by 0.0825, we get:
[tex]\begin{gathered} \text{Total cost = \$899 + (\$899)}\cdot(0.0825) \\ \text{Total cost = \$973.1675} \end{gathered}[/tex]
It means that you need to save $973.1675 to buy your new iPhone.
Then, every week you save 15% of $565. This quantity is calculated as:
[tex]\text{save per week = \$565 }\cdot\text{ 0.15 = \$84.75 per week}[/tex]
So, every week you save $84.75
Finally, to calculate the number of weeks that you need to buy the new iPhone we need to divide the total cost by the quantity saved per week as:
[tex]\text{Weeks}=\frac{\text{ \$973.1675}}{\text{ \$84.75}}=11.48\text{ weeks}[/tex]
Therefore, the answer is 11.48 weeks
Answer: 11.48 weeks
