Problem 10 (a) A teacher selects a team of three from a group of students. She also
selects a team of two (students can be in more than one team). The
teacher notices that there are twice as many ways of choosing the
team of three as there are the team of two. How many students are
in the group?
(b) For another group of students, there are three times as many teams
of three which can be selected as there are teams of two. How many
teams of three can be selected from this group?