Answer:
6
Explanation:
To solve this problem, you are supposed to take the GCF of 60 and 42.
Factors of 42: 1,2,3,6,7,14,21
Factors of 60: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30
The common numbers are: 1,2,3,6
The greatest common factor is 6.
So, the greatest number of boxes she can make are 6