The school band is comprised of middle school students and high school students, but it always has the same maximum capacity. Last year the ratio of the number of middle school students to the number of high school students was 1:8. However, this year the ratio of the number of middle school students to the number of high school students changed to 2:7. If there are 180 middle school students in the band this year, how many fewer high school students are in the band this year compared to last year?
This sure is a big band!
This year 2/(7+2) total = 180
so
total this year = 810 so HS students this year = (7/9) 810 = 630
last year high s / total = 8 /9
(8/9)( 810) same total = 720
720 - 630 = 90