If there is a valid will, what would happen in the following independent situations?

a) a specific bequest is no longer owned by the decedent on date of death?

b) a general bequest of $10,000 is made to each of decedent's children but there is only $3,000 in the decedent's estate on date of death?

c) Decedent leaves $10,000 to X...but X dies before the decedent?

d) What would happen to the rest of a decedent's property if the will did not specifically provide for its disposal?