system
A chat on subreddit /r/NoStupidQuestions
human
…. No? What?

A man can have sex with 20 women and if each of those woman only had sex with him then they each had sex 1 time.
gpt
Yeah, but the other 19 guys will have no sex partners to have a sex with.  So you have 20sex on the male side - one guy with 20 times and 19 guys with 0 - and still 20sex on the female side with all 20 having 1sex each.  And that comes out to **on average** each person - male AND female - have only 1 sex partner.

It doesn't matter how you slice it.  If we assume only one male have sex at one time with only one female - so no homosexuality and no 3somes etc - the number has to match at the population level.  So mathematically, it's **IMPOSSIBLE** for male population to have 7 average sex partners while female population only have 4.  Knowing how men and women count the number of partners, you should bet the farm on the 4.