Selina claims single having one exemption. her state tax deduction is 21% of her federal tax contribution. calculate the amount of state tax selina owes if her gross pay for two weeks is $840

Okay since Selina claims to have 1 tax exemption and also makes 840$ using the chart provided we can find the amount of income tax that is being withheld.
So this gives us 77$ on the chart this is "The Federal Income Tax" (77$ X 0.21) = 16.17$ which is answer A. 16.17$