Amongst Orthodox and most Conservative groups, a minyan is made up of 10 Jewish men.
Amongst most other groups, a minyan can be made up 10 Jewish men and/or women.
In orthodox services, 10 males make up a minyan. In non-Orthodox services, women are also counted in minyans. Since a Bar Mitzvah is held during a service, it would require a minyan.
4 people
20 people
Lots of people
6
One.
2
The exact number of people it takes to make a medieval catapult. :-)
200,000
1000
13,765 people
100