Question

there are 16 sixth graders and 20 seventh graders in a club. the club wants to organize members into equal size groups. each group will only have sixth or only seventh graders.

how many students will be in each group if each group has the greatest number if club members

Answer 1

sixth graders can have 4 groups of 4
seventh graders can have 5 groups of 4

Answer 2

Finding the Least Common Multiple, 4, we can easily then divide each group (6th and 7 graders) by 4.
16 6th graders ÷ 4 = 4 groups
20 7th graders ÷ 4 = 5 groups
So, the the 6th graders will have 4 groups each with 4 people (LCM).
The 7th graders will have 5 groups each also with 4 people ( LCM).
Hope this helps!