What is the probability Lucy and Maya will be on the same team?

Question

Lucy, maya and 4 others are playing a game. They are splitting up into 2 teams of 3.

Answer 1

There are 10 ways of combining 6 team members. Call them A, B, C, D, L and M, where L is Lucy and M is Maya.
Here are all the possible teams:
ABC DLM, ABD CLM, ABL CDM, ABM CDL, BCD ALM,
BCL ADM, BCM ADL, ACD BLM, ACL BDM, ACM BDL.
You can see that LM appear in the same team 4 times. So the probability that Lucy and Maya are in the same team is 4/10 or 2/5.
Another way of looking at it is that the possibilities must include Lucy and Maya sharing their team with each of the 4 other members.