Neutron Decay a neutron at rest decays (breaks up) to a proton and an electron. Energy is

Question:

Neutron Decay a neutron at rest decays (breaks up) to a proton and an electron. Energy is released in the decay and appears as kinetic energy of the proton and electron. The mass of a proton is 1836 times the mass of an electron. What fraction of the total energy released goes into the kinetic energy of the proton?