12 : 15 12 : 14
697÷( 12+ 15+ 14)= 17
Lower grade: 17 × 12 = 204 (person)
Mid-range: 17× 15 =255 people
Senior grade: 17× 14 =238 (person)
A: There are 204 junior students, 255 senior students and 238 senior students.