Ben and molly are married and will file jointly. ben generates $300,000 of qualified business income from his single-member llc (a law firm). he reports his business as a sole proprietorship. wages paid by the law firm amount to $40,000; the law firm has no significant property. molly is employed as a tax manager by a local cpa firm. their modified taxable income is $381,400 (this is also their taxable income before the deduction for qualified business income). determine their allowable qbi deduction. $