What would a judge say about fair splitting of costs between divorced parents?

Divorced parents P1 and P2 of high-schooler H1 have existing agreement to split the cost of H1's college education. P1 remarries somebody who's generous employer pays a good chunk of college tuition for children and stepchildren. If the tuition is $10,000, and generous employer pays $5,000, would a judge say that P1 and P2 must split the remaining $5,000, or would a judge say that P2 should pay the remaining $5000?What would a judge say about fair splitting of costs between divorced parents?
P2 should pay the $5,000. Where P1 got his/her share of the tuition is irrelevant.What would a judge say about fair splitting of costs between divorced parents?
this is hard for someone to take and say what should be done but according to my opinion they should seat face to face to have a open discussion. i know its hard but it is the question of someone's study may be then it can be tried. so i prefer to leave this matter on them i think they will be solving it in a best way
P2 SHOULD HAVE TO PAY THE REST P1 FOUND A WAY TO PAY THERE HALF NOW P2 SHOULD HAVE TO PAY THERE'S