1. The problem statement, all variables and given/known data A nucleus of mass M + m1 is at rest and decays into two daughter nuclei of equal mass M/2 each. The binding energy per nucleon for the parent nucleus is A and that for the daughter nucleus is B. Which is greater A or B? 2. Relevant equations Binding energy per nucleon= Mass defect of nucleus / mass number 3. The attempt at a solution I am unable to link the given masses of nuclei (parent and daughters) with their mass defect in the absence of data on A and Z. I need a few hints on how to proceed with tackling this problem.