The number of hydrogen bonded molecules present in ${\mathrm{CuSO}}_{4.}5{\mathrm{H}}_2\mathrm{O} \mathrm{is}$

In CuSO₄​.5H_2​O, Cu is coordinated with 4 water molecules and two more oxygen atoms from Sulphate ion.

Now fifth water molecule is hydrogen-bonded and is deeply embedded in a crystal. It is not coordinated.