Answer:if there are 7 HS students for every 2 MS students and there are 18 MS students...
18/2 = 9
9(7) = 63
So, there are 18 + 63 = 81 total students.
Since we had 9 parts last year also (1:8), 81/9 = 9 students are in each part. 8 students in each part are HS and one is MS.
8(9) = 72 HS students last year.
72 - 63 = 9 fewer HS students than last year.
Hope this helps!
