Bill Jackson worked during school and during the first 2 months of his summer vacation. After factoring in his deductions and personal exemption as a single man, Bill found that he had a total taxable income of $1800. Bill's employer wants him to work another month during the summer, but Bill had planned to spend the month hiking. If an additional month's work would increase Bill's taxable income by $1600, how much more money would he have after paying the income tax? (Answer: $1440)