1.
Binding energy per nucleon of a fixed nucleus AX^A X is 8 MeV8\,\text{MeV}. It absorbs a neutron moving with kinetic energy 2 MeV2\,\text{MeV} and converts into YY, emitting two photons of energy 1 MeV1\,\text{MeV} and 4 MeV4\,\text{MeV} respectively one after the other. The binding energy per nucleon of YY (in MeV) is