I just need help with B. -thank you!

Marcia, a single individual, has qualified trade or business income of $240,000. Her business paid $80,000 of W-2 wages this year and has $50,000 of tangible business property. a. Compute Marcia's QBI deduction, assuming her overall taxable income before QBI is $300,000. b. Compute Marcia's QBI deduction, assuming her overall taxable income before QBI is $180,000