D transferred property to T, as trustee, in trust, the income to be paid to X for X's life,remainder to Y if living at X's death or, if not,remainder to Z or Z's estate.

Will a part of the value of the property be included in Zs gross estate if Z dies survived by X but not by Y? In the current year, what amount, if any, would be included in Zs gross estate if the trust corpus is worth $100,00, X is 60 years old, the Section 7520(a)(2) interest rate is 4 percent, and Zs estate uses a date-of-death valuation?