Atoms and Nuclei: JEE Main 2012 Physics question

Assume that a neutron breaks into a proton and an electron. The energy released during this process is : (mass of neutron $= 1.6725 \times {10^{ - 27}}kg,$ mass of proton $= 1.6725 \times {10^{ - 27}}\,kg,$ mass of electron $= 9 \times {10^{ - 31}}\,kg$ ).