Jane and Robert Brown are married and have eight children, all of whom are eligible to be claimed as the couple's dependents. Robert earns $94,000 working as an accountant, and Jane earns $35,000 as a teaching aide.

Given their large family, the Browns live in a frugal manner. The family maintains a large garden and some fruit trees from which they get most of their produce, and the children take family and consumer science classes so that they can help make the family's clothing.

The Browns record no gross income other than their salaries (all of their investment income is earned from qualified retirement savings), and their itemized deductions are less than the standard deduction. The Browns report no other AMT adjustments or preferences.

a. What is the couple's 2015 regular tax liability?

b. What is the couple's 2015 AMT?