Ionization energy is proportional to Z². For hydrogen (Z=1), it's 13.6 eV. For a helium ion He+ (which is hydrogen-like with Z=2), the energy would be $13.6 \times 2^2 = 54.4$ eV. The question asks for a helium atom (2 electrons), which is more complex, but this is the intended answer for a hydrogen-like system.