PLEASE HELP I WILL MARK BRAINLIEST

Answer:
he can choose two teams, because if there are 10 people and he is putting 5 in each team he can only have 2 teams.
there can only be 3 groups of sprinters, there will be one person that can not be in a group unless there is one group of 4. but if there can only be 4 in each group then you can only make 3 groups of 4.
and i dont know how to do the last two. sorry.
Step-by-step explanation: