What is the maximum IRA contribution that Mr. Janson can make under each of the following assumptions?

Required:

1. He is age 20 and single. His only income item is $13,600 interest from a trust fund.
2. He is age 40 and single. His only income item is a $34,600 share of ordinary income from a partnership.
3. He is age 60 and single. His only income item is $29,000 wages from his job.
4. He is age 46 and files a joint return with his wife. His sole proprietorship generates a $7,390 loss, and his wifes salary is $49,800.