Eisenhower was the last president born in the 19th century, and at age 62, was the oldest man elected President since James Buchanan in 1856 (President Truman stood at 64 in 1948 as the incumbent president at the time of his election four years earlier). Eisenhower was the only general to serve as President in the 20th century and the most recent President to have never held elected office prior to the Presidency (The other Presidents who did not have prior elected office were Zachary Taylor, Ulysses S. Grant, William Howard Taft and Herbert Hoover).
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): In what century was Eisenhower born?
Ah, so.. 19th

Possibly the first house erected within the site was that of a Sir William Blake, around 1624. The next owner was Lord Goring, who from 1633 extended Blake's house and developed much of today's garden, then known as Goring Great Garden. He did not, however, obtain the freehold interest in the mulberry garden. Unbeknown to Goring, in 1640 the document "failed to pass the Great Seal before King Charles I fled London, which it needed to do for legal execution". It was this critical omission that helped the British royal family regain the freehold under King George III.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What was Lord Goring's garden known as?
Ah, so.. Goring Great Garden

Rapid environmental changes typically cause mass extinctions. More than 99 percent of all species, amounting to over five billion species, that ever lived on Earth are estimated to be extinct. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described. The total amount of related DNA base pairs on Earth is estimated at 5.0 x 1037, and weighs 50 billion tonnes. In comparison, the total mass of the biosphere has been estimated to be as much as 4 TtC (trillion tons of carbon).
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): How many DNA base pairs are on earth?
Ah, so..
unanswerable