Answer:
A: 7
B: 8
C: 6
Step-by-step explanation:
You have to try to find the the same greatest factor of both of the numbers.
Since both of the numbers are divisible by 7 the number of groups equals 7.
So you divide the number of girls, which is 56, by 7, the number of girls in each group is 8.
Then you divide the number of boys, which is 42, by 7, the number of boys in each group is 6.