In modern speech
五五 almost always means "50-50 / equal share," especially in
五五分成 (wǔwǔ fēnchéng, split equally) and
五五开 (wǔwǔ kāi, even odds — popularized online by gaming streamer
卢本伟 / Lu Benwei after his "
五五开 not addicted" controversy). The classical sense "twenty-five" survives only in literary references to
三年之丧 (a 25-month mourning period in the Book of Rites).