However, the time machine is set to '17 years ago', this would make present Trunks 18 years old. Since Super is 5 years after the Boo arc, he's supposed to be 36 years old currently. Now with Super, 7 years have passed since the Cell arc and the Boo arc, and the two timelines run parallel to each-other according to the manga, so he'd be at least 31 by the time the Boo arc came along. Then he goes back to the future, kills the androids, waits 3 years, and kills Cell, he's 24 years old by the last time we saw him in DBZ.
Against the androids, three years later, he's 20. He was 17 when he came back for the first time.
