Q: In this task, you're given a passage, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both passage and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the passage or linked information.
Passage: Fiser was born in Zagreb on June 13, 1905 to a Jewish family of well-known Croatian architect Ignjat Fischer and his wife Helena (nee Egersrodfer). She attended elementary and music school in Zagreb. Fiser graduated from the Academy of Music, University of Zagreb under Fran Lhotka as the first female conductor in Croatia. Soon after she left for Salzburg where she was perfecting herself at the Mozarteum University of Salzburg. From 1931 to 1934, Fiser worked as violinist at the Croatian Music Institute orchestra. As a conductor, Fiser debuted in 1933 while directing the comic opera Bastien und Bastienne with Zagreb philharmonic orchestra. From 1939 to 1941, she led the Zagreb Red Cross orchestra. Until 1941, she also led the Osijek philharmonic orchestra. From 1947 to 1965, Fiser worked as a prompter at the Croatian National Theatre in Zagreb.
Link Information: Ignjat Nathan Fischer (18 June 1870, Zagreb 19 January 1948, Zagreb) Answer: 35
A:
How old was Fiser's father when she was born?