Paris and Amsterdam travel time

In the beginning stages of planning an Amsterdam and Paris trip for my son's 16th birthday (surprise for him but he's been talking about wanting to do this trip). Realistically how many days in each city without being too rushed? Paris will include a day trip to Versailles. Traveling from either NY or Boston I'm thinking 11 days including travel. 3 full days in Amsterdam and 5 in Paris. 1 train travel day in the middle so additional 1/2 day in Paris.