You can select 7 persons to one group from 14 persons in = = 3432 different ways. ANSWER
As soon as you select 7 persons from 14 for one group,
the second group is formed AUTOMATICALLY from the rest of people.
So, the number of ways to form two groups of 7 from 14 people is the same,
as the number of ways to form two groups of 7 each from 14 people.
ANSWER. 3432 different ways.
Solved.
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Since the order of persons does not matter, this problem is on COMBINATIONS.