<span>Gross pay increases by >$20 and withholding allowances stay the same is the answer that you are looking for!
Hope this helps!</span>
6 feet * 7 feet = 42 feet²
18 feet * 21 feet = 378 feet²
42 feet² was painted for $52
1 feet² will be painted for $52/42
378 feet² will then be painted for: ($52/42) * 378
= $468
Hence 18 feet by 21 feet will be painted for $468
Hope this helps.