The binding energy of e- in ground state of hydrogen atom is 13.6 eV. The energies required to eject out an electron from three lowest states of ${\mathrm{He}}^{+}$ atom will be (in eV):

The hydrogen atom's ground state has a binding energy of 13.6 eV for e. Three of the lowest states of the H, e+ atom will require energies of 54.4, 13.6, and 6 eV, respectively, to eject an electron.
Energy is inversely proportional to $\frac{{\mathrm{Z}}^2}{{\mathrm{n}}^2}$.
H is atomic energy in its ground state is 13.6 eV.
An electron must expend a certain amount of energy to leave ${\mathrm{He}}^{+}$is first lowest state.${\mathrm{E}}_1=\frac{{\mathrm{Z}}^2}{{\mathrm{n}}^2}\mathrm{E}=\frac{2^2}{1^2}13.6=54.4$

In the second-lowest state of He+, the energy needed to release one electron is ${\mathrm{E}}_2=\frac{{\mathrm{Z}}^2}{{\mathrm{n}}^2}\mathrm{E}=\frac{2^2}{2^2}13.6=13.6$

In the third-lowest state of He+, the energy needed to release one electron is ${\mathrm{E}}_3=\frac{{\mathrm{Z}}^2}{{\mathrm{n}}^2}\mathrm{E}=\frac{2^2}{3^2}13.6=6$