Question

Fifteen students were divided into two classrooms in a ratio of 1:2.

Answer 1

The answer: In Classroom 1, there are 5 students while in Classroom 2, there are 10 students.

Explanation:
x + 2x = 3x
3x = 15
x = 5, Classroom 1 = 5, Classroom 2 = 5 x 2 = 10

I hope that this helps! :)