Pesachim8: 7
אֵין שׁוֹחֲטִין אֶת הַפֶּסַח עַל הַיָּחִיד, דִּבְרֵי רַבִּי יְהוּדָה; וְרַבִּי יוֹסֵי מַתִּיר.  אֲפִלּוּ חֲבוּרָה שֶׁל מֵאָה שֶׁאֵין יְכוֹלִין לֶאֱכוֹל כְּזַיִת — אֵין שׁוֹחֲטִין עֲלֵיהֶן.  וְאֵין עוֹשִׂין חֲבוּרַת נָשִׁים וַעֲבָדִים וּקְטַנִּים.
They may not slaughter the pesach-offering for an individual —- [these are] the words of R' Yehudah. [But] R' Yose permits [this].  Even [if] a group [consists of] a hundred [people], if they are unable to eat the volume of an olive, we may not slaughter on their behalf.  We may not form a group [solely] of women, slaves, and minors.