How many different two-person teams can be made from 6 people?
A 2 person team can be chosen in one of fifteen ways.
The question is not precise because if you treated it literally the answer would be 3. First you choose one team, 4 people are left in the group, the second team takes another 2 people and the remaining create the third team.
But I assume that the question is like "In how many ways a 2 people team can be chosen from 6 people?"
Such question has an answer
There is also another way of calculating the number. A team of 2 chosen from six people is (in mathematics) a 2 element combination of a six element set.
The number of such combinations can be calculated as: