9. In the first month after opening, a mobile phone shop sold 300 phones. A model for future sales assumes that the number of phones sold will increase by \(5 \%\) per month, so that \(300 \times 1.05\) will be sold in the second month, \(300 \times 1.05 ^ { 2 }\) in the third month, and so on.
Using this model, calculate
- the number of phones sold in the 24th month,
- the total number of phones sold over the whole 24 months.
This model predicts that, in the \(N\) th month, the number of phones sold in that month exceeds 3000 for the first time.
- Find the value of \(N\).