Question

The Neumann Morgenstern approach to choice under certainty.

Answer 1

The von Neumann-Morgenstern utility theorem shows that, under certain axioms of rational behavior, a decision-maker faced with risky (probabilistic) outcomes of different choices will behave as if he or she is maximizing the expected value of some function defined over the potential outcomes at some specified point in the future.
Source:
https://en.m.wikipedia.org/wiki/Von_Neumann–Morgenstern_utility_theorem