Question 511780
The arithmetic average = total of all students' scores / number of students.
avg = total/count
so
count*avg = total
.
We do not know the count in the second class, but we know the average, so we can use the average.
The count in the second class = x.
So the combined count in the two classes = 30+x.
.
30*84 + x*96 = (30+x)*88
.
2520 + 96x = 2640 +88x
8x = 120
x = 15
There are 15 students in the second class.
.
Done.