No More Than 190

My daughter and I are struggling with the invite list. We can only accomodate 190 for a sit down dinner. They are young, so we are springing for the wedding.
The problem is, we have 2 large families and they have about 55 college age friends they want to include. Our daughter is having trouble with the idea that we have a larger invite list than anybody else,
We on ther other hand feel family and our friends should make up a somewhat larger part of the list.
Our fear is that the college friends will not realize that if they don`t make it after RSVPing YES, WE WILL BE PAYING for expensive meals ANYWAY. We have already cut most of the couples we have been friends with for many years. How would you split the numbers?
What percentage should the mother and father of the bride get? Right now we have 50% with mostly family.