A group in IAM can contain many users.
Can a user belong to multiple groups?
Yes, a user can be a member of up to 150 groups.
Yes, a user can be a member of up to 50 groups.
Yes, a user can be a member of up to 100 groups.
Yes, a user can be a member of up to 10 groups.
Explanations:
IAM users can be a member of a maximum of 10 groups, not 150.
IAM users can be a member of a maximum of 10 groups, not 50.
IAM users can be a member of a maximum of 10 groups, not 100.
AWS IAM allows each user to be a member of up to 10 groups.
If memory serves me right, the answer is:
Yes, a user can be a member of up to 10 groups.