Final answer:
The QBI deduction for Tanuja in 2018 is $78,000.
Step-by-step explanation:
The QBI deduction allows certain business owners to deduct up to 20% of their qualified business income. To calculate the QBI deduction, we need to determine Tanuja's QBI, which is $540,000 in this case. Next, we need to calculate the W-2 wage limitation, which is the greater of 50% of the W-2 wages or 25% of the W-2 wages plus 2.5% of the unadjusted basis of property. In this case, the W-2 wage limitation is $78,200. Finally, we need to calculate the QBI deduction, which is the lesser of 20% of the QBI or the taxable income minus the W-2 wage limitation. Since the taxable income before the QBI deduction is $475,000 and the W-2 wage limitation is $78,200, the QBI deduction for Tanuja is $78,000.