John died in 2016. What amount, if any, was included in his gross estate in each of the following situations:
a. In 1997, John created a revocable trust, funded it with $400,000 of assets, and named a bank as trustee. The trust instrument provided that the income is payable to John annually for life. Upon John's death, the assets were to be divided equally among John's descendants. When John died at the age of 72, the trust was still revocable. The trust assets were then worth $480,000.
b. In 2005, John transferred title to his personal residence to a charitable organization but retained the right to live there rent free for 20 years. The residence was worth $150,000 on the transfer date. At John's death, the residence was worth $230,000.
c. In 2000, John created an irrevocable trust, funded it with $200,000 of assets, and named a bank as trustee. According to the trust agreement, all the trust income was to be paid out annually for 25 years. The trustee, however, is to decide how much income to pay each year to each of the three beneficiaries (John's children). Upon termination of the trust, the assets are to be distributed equally among John's three children (now adults) or their estates. The trust's assets were worth $500,000 when John died.
d. In 1997, John created an irrevocable trust with a bank named as trustee. He designated his grandson Al as the beneficiary of all the income for life. Upon Al's death, the property is to be distributed equally among Al's descendants. The trust assets were worth $400,000 when John died.