The correct pair of linear equations that models the situation is:
- \( p + c = 25 \) (This represents the total number of student council members, which is 25.)
- \( 15p + 10c = 300 \) (This represents the total amount of money raised, where the principal pays $15 for each member picking up litter and $10 for each member cleaning the hallways, totaling $300.)
So, the response is:
\( p + c = 25 \); \( 15p + 10c = 300 \)