What are the odds of both my Grandmothers passing away on the same 24 hour day? [duplicate]

• Sorry for your loss - my condolences. All days being equally likely, and assuming independence, there are $365^2$ possibilities for choosing two days, but only $365$ for choosing a common day. The chances of this happening are ${365 \over 365^2} = {1 \over 365}$, therefore. – Ami Tavory Apr 8 '18 at 12:56