To win any trivia game on a presidential age question, you must listen very carefully to the wording.
The youngest person ever ELECTED president was John F. Kennedy at age 43. The youngest person ever to BECOME president was Teddy Roosevelt at age 42, when he assumed the office after William McKinley’s assassination.
The oldest persons ever ELECTED president were both Joe Biden and Donald Trump at age 78, though when using each’s inauguration day, Trump was slightly older by days.
The oldest person ever to BE president was Joe Biden, who was 82 when he departed office. If Trump completes his full second term, he too would be 82 upon departing, but Trump would have more days at 82 than Biden, thus making him technically the oldest person to be in that office (his last day is January 20, 2029).
Prior to Biden and Trump, Ronald Reagan was the oldest president. He was 69 upon assuming the office in 1981 and 77 when departing it in 1989.
As for longevity, to date, only former President Jimmy Carter has made it to the 100-year-old mark.
