Ratio of the number of students in art class to the number of students in gym class was 2:7, however art class is small, and gym class is large, students changed for the second semester. Now the students in art class to the number students in gym class is 5:4. If 75 students are in art class in second semester, how many were in art class and gym class first semester?
Accepted Solution
A:
semester 1:
let the number of students in the art class be 2a, and the number of the students in the gym class be 7a. (check: the ratio is 2a:7a = 2:7)
so the total number of students is 9a.
semester 2:
the 9a students are go to the art class and gym class at a a ratio of 5: 4,
so 5a students go to the art class, and 4a students go to the gym class.
75 students are in art class in second semester means that 5a=75,