Write the ratio as a unit rate. Simplify. 216 diving student and 12 instructor

Ratio students to classroom in school A equals 216:12 which simplifies to 18:1. Ratio students to classroom in school B equals 104:4 which simplifies to 26:1.Total students combining school A and B equals 216+104=320 and Total classroom 12+4=16, if both school combined are assumed to be a single school C, than ratio of of students to the classroom in school C equals 320:16 which simplifies to 20:1 which means 20 students in every classroom, now total students in 4 classroom of School C equals 20x4=80, these 4 classroom are separated as School B and other 12 classroom School A, now ratio still 20:1 (same in both schools). initially students in School B were 104 and now are 80, then total students transferred equals 104-80= 24.