What is the effective atomic number $(EAN)$ of $Zn$ in $[Zn(NH_3)_4]SO_4$? (Atomic number of $Zn = 30$)

Which of the following pairs is not correctly matched?

In $[Ni(NH_3)_4]SO_4$,the $E.A.N.$ of $Ni$ is

The effective atomic number $(EAN)$ of iron in the complex $[(\eta^5 - C_5H_5) Fe(CO)_2Cl]$ is

Among $V(CO)_6$,$Cr(CO)_5$,$Cu(CO)_3$,$Mn(CO)_5$,$Fe(CO)_5$,$[Co(CO)_3]^{3-}$,$[Cr(CO)_4]^{4-}$,and $Ir(CO)_3$,the total number of species isoelectronic with $Ni(CO)_4$ is. . . . . [Given atomic number : $V=23$,$Cr=24$,$Mn=25$,$Fe=26$,$Co=27$,$Ni=28$,$Cu=29$,$Ir=77$ ]

What is the $EAN$ of $Fe$ in $[Fe(CN)_6]^{3-}$?