In a recent year, a single person could expect to pay $4200 in income taxes on an adjusted gross income of $30,000. How much more tax should the person expect to pay if her adjusted gross income increased by $3000, knowing that this would not move her into the higher tax bracket? She should expect to pay how much more in taxes.

2 answers

42/300 * 3/30
oops. for raw increase,

42/300 * 3