Fraction of Cepheids in binaries and triples as a function of the initial stellar mass of the embedded cluster where the Cepheids formed. Left panel: fraction of Cepheids in binaries of orbital period shorter than 10¹⁰ days. The fraction for Cepheids occurring in clusters and in the field is plotted separately by solid and dashed lines, respectively. Clusters at different galactocentric radii are shown by symbols, and clusters of different metallicity are shown by colours. Some of the Cepheids in binaries are orbited by an outer body, namely, they are the inner binary of a triple. Right panel: fraction of Cepheids in triples where the orbital period of the outer body is shorter than 10¹⁰ days. The meaning of the symbols is the same as in the left panel.