2<3<1
2<1<3
3<1<2
1<2<3
As the polarity of C=O bond decreases hydration decreases. In compound 3 polarity is least due to +I effect of tert-butyl. Compound 2 is most polar among the given compounds as +I effect will be less in 2 compared to 1. So the order would be 3<1<2