Respuesta :

Sure:
90 year old parents : 60 year old children (had kids at 30; very reasonable)
60 year old parents : 40 year old children (had kids at 20; unlikly but possible)
45 year old parents : 30 year old children (had kids at 15; very unlikly but not impossible)
 
Yes. If your parent is 90 then it means you are 60. Which then means that they had you when they were 30 which is normal.