Determine the AMT exemption amount for each of the following taxpayers:

a. Nominal Corporation has an alternative minimum taxable income of $140,000.

b. Janine is a single individual with an alternative minimum taxable income of $155,000.

c. Jagged Corporation has an alternative minimum taxable income of $220,000.

d. Peter and Wendy have an alternative minimum taxable income of $110,000.

e. Popup Corporation has an alternative minimum taxable income of $900,000.