Final answer:
It will take Kevin 3 weeks to empty his bank account completely.
Step-by-step explanation:
Kevin has $450 in his bank account and spends $150 per week. So, he will spend $150 in the first week and his balance will be $450 - $150 = $300.
In the second week, he will spend another $150, leaving his balance at $300 - $150 = $150.
In the third week, he will spend the final $150, resulting in a balance of $150 - $150 = $0.
Therefore, it will take 3 weeks for Kevin to empty his bank account completely.