The number of water molecule(s) directly bonded to the metal centre in ${\mathrm{CuSO}}_4. 5{\mathrm{H}}_2\mathrm{O}$ is:

The metal ion in ${\mathrm{CuSO}}_4. 5{\mathrm{H}}_2\mathrm{O}$ is six coordinated. Water molecules coupled to cations and oxygen atoms of sulphate ions hold together the fifth ${\mathrm{H}}_2\mathrm{O}$ molecule in the coordination groups that surround the cupric ion.

The coordination groups are made up of $4{\mathrm{H}}_2\mathrm{O}$and two oxygen atoms of sulphate ions. 
The quantity of water molecules that are tightly bound to the metal centre in. ${\mathrm{CuSO}}_4. 5{\mathrm{H}}_2\mathrm{O}$ in 4.