Hi Zina,
The question is asking if the students can be divided into 2 groups and/or 4 groups and or 6 groups . . .
The number of groups should be an even number and a common factor for 60 and 40. So you can't have 40 people in one group because 40 doesn't go into 60.
So what even numbers do go into 40 & 60?
2, 4, 10 and 20
So you can 2 groups where each group as 30 grade 8 students and 20 grade 7 students
4 groups where each group as 15 grade 8 students and 10 grade 7 students.
How many grade 8 and grade 7 students are there in each of the 10 groups and each of the 20 groups?
Dan
After thinking a little more about this question, you can also use the odd number of groups that factor into 60 and 40.
Can you think of any?