Require help with a solver constraint

Hey, i just need a bit of help finishing this solver question.
I wrote out all the constraints algebraically and don't seem to have any issues. The only thing I'm confused about is how to represent (in excel) that for every 2 counselors there are up to 3 aides.
Thus far i have z representing the total number of employees where:
Z is less than or equal to 45
Z is greater than or equal to 30
X represents the counsellers, y represents the aides
2400x+1100y is what we are trying to minimize
Solver1.jpg