The real problem is when frodo is asking this question and it could be anywhere between ~30 and ~50... the age relationship between frodo and bilbo is incorrecr. it should be either 111 - 30 or 131 and 50

Edit: just remembered, frodo was 33 when he got the ring. On the books, some invetees to bilbos party where pissed off cause they felt like they were invited just to cover the 144 main guests (adding both bilbo's and frodo's age at the time)