David has a job selling mobile phone plans. His weekly salary, `W` dollars, is calculated using the rule below:
`W = 300 + 0.05 P`
where `P` is the total value in dollars of the mobile phone plans he sells that week.
David sold $32 000 worth of mobile phone plans in a given week.
What was David's salary in the week?
- `$640`
- `$1280`
- `$1900`
- `$3230`