Who knows seventy-five?
Please cite/link your sources, if possible. At some point in the next few days, I will:
Upvote all interesting answers.
Accept the best answer.
Go on to the next number.
Depending on your count, seventy-five are the tractates of the Mishna (63) plus the minor tractates:
Seventy-five was Avraham's age (then "Avram") when he left for Israel. Though this was not the first move in his life; it appears his father had initiated a move and hadn't completed it.
להם ("to them") has Gematria 75, and it appears more often in Tanach than all other 75-words combined.
Every book of Tanach (counting the Twelve individually) contains at least one 75-word, except for Nachum.
75 are the years that Avraham and Yitzchak lived as contemporaries (since Sarah bore Yitzchak when Avraham was 100 years old, and he lived to 175).