Impossible Entrance Question From Harvard University

Jill and Bob have been married 9 years. Bob's brother Duane is 2 years older than his youngest sibling. Jill and Duane both graduated from high school in 1977. Bob's mother was born in 1959 and had all three of her kids before she was 28, the third being born when her husband was 29. Jill's parents Sue and Chris are both the same age, and only Chris was divorced once when he was 24. Chris's ex