Here was the best explanation I found in the Toot link above: @[email protected] ... it's not a riddle. each phrase is merely a statement of fact.
"What" is a word made up of 4 letters.
"Yet" is made up of 3.
"Although" is written with 8 letters"
and "then" with 4.
"Rarely" consists of 6, and
"never" is written with 5.
it's not actually asking for an answer