Question: who was the oldest us president in office
Answer: The oldest person at the time of entering office was Donald Trump , at the age of 7004257880000000000 ♠ 70 years , 220 days ; Ronald Reagan was the oldest person in office , at the age of 7004284730000000000 ♠ 77 years , 349 days when his presidency ended in January 1989 .