Answer:
The music director could make 15 groups of performers with 6 6th grade students and 5 7th grade students in each group.
Explanation:
Since in the question it is mentioned that
There is 90 6th grade students and 75 7th grade students
Now factor could be done in the following ways
90 = 2 × 45 = 2 × 3 × 15 = 2 × 3 × 3 × 5
75 = 3 × 25 = 3 × 5 × 5
Now the GCF of 90 and 75 is
= 3 × 5
= 15
So,
90 = 15 × 6
75 = 15 × 5
Hence, The music director could make 15 groups of performers with 6 6th grade students and 5 7th grade students in each group.