the average grade of students in Group A is 4.
the average grade of students in Group B is 3.
If the groups were merged into one group, what is the average of the group?
1. there are twice as many students in group1 as in group 2
2. There are 4 more students in group 2 than group 1.
Useing 1 Assume group 2 has 1 student then group 1 has 2 students
new avg = (4*2+3*1)/3 Suff
Using 2 B-A=4 insuff we need to some how know the ratio of people in A and B