In 2018, married filing separately taxpayers only receive a standard deduction of $12,000 compared to the $24,000 offered to those who filed jointly. If you file a separate return from your spouse, you are automatically disqualified from several of the tax deductions and credits mentioned earlier.
Solution:
2/3=0.66
3/6=0.5
5/9=0.55
0.66+0.5+0.55=1.71