Answer: It looks like you just need to cut off the last vowel (and consonant if there is one) of the word.
For number one, it's "perezosísimo"
For question 2, it's "aburridísimo"
For question 3, I think you do the same but keep it plural, so "interesantísimos" I would imagine.
B) El hace ejercicios para estar en forma.
