The number of 5 people groups that can be selected from 9 people when two particular persons are not to be in the same group is
Step-by-step Solution:
\[ \text{We have to select a group of 5 people from 9 people such that two particular persons are not selected together.} \] \[ \text{Number of ways} = \text{(Total ways to select 5 people from 9)} - \text{(Ways where both particular persons are in the group)} \] \[ = \binom{9}{5} - \binom{7}{3} \] \[ = 126 - 35 \] \[ = 91 \]