Aschool bus has 25 seats, with 5 rows of 5 seats. 15 students from the first grade and 5 students from the second grade travel in the bus. how many ways can the students be seated if all the first-grade students occupy the first 3 rows?

Which lines are parallel? justify your answer. lines p and q are parallel because same side interior angles are congruent. lines p and q are parallel because alternate exterior angles are congruent lines l and m are parallel because same side interior angles are supplementary lines l and m are parallel because alternate interior angles are supplementary.