Top to bottom: Single stars, single stars with extinction, binary stars with exact-distance analysis, and binary stars with inexact-distance analysis. Primary-star mass and age histograms for the input systems (black solid line) and output fits (red dotted line). The mass and age distributions change as a result of the presence of undetected binaries: the changes in the mass distribution are small, but the median age is pulled younger and the morphology of the distribution changes.