In the April 2019 issue of NAFEMS BENCHMARK magazine, two challenge problems are presented. The first one consists of two normal distributions, producing an analytical (theoretical) solution. The second one contains several distributions (normal, uniform and lognormal), and therefore an exact solution is not available. At the NAFEMS World Congress 2019 these problems were discussed and a few solutions were presented. In this presentation these solutions and additional ones are discussed in combination with the theoretical background and the pitfalls of these methods.