A penguin. If all four walls face north the house must be at the southernmost point of the earth. Really, any native antarctic bird would work.
This brain teaser is quite similar to the guy whose house walls face south and sees a bear, then you’re asked the color of the bear. The bear would be white (a polar bear) as they’re the only bears indigenous to the north pole. A lawyer would claim it’s all circumstantial evidence and the bear could be an imported brown bear. The lawyer makes a valid point.
It cannot be seen, it cannot be felt,
Cannot be heard, cannot be smelt,
Lies behind stars and under hills,
And empty holes it fills.
Comes first follows after,
Ends life kills laughter.
Joe and Andrea want to copy three 60-minute cassette tapes. They have a 2-cassette recorder to copy the tapes, allowing them to copy two tapes at a time. Each side takes 30 minutes to be copied, so two tapes can be copied in an hour and the third will take another hour. Andrea bets Joe she can copy all three tapes in 90 minutes. Does she win the bet?
In the first 30 minutes Andrea copies the A sides of tape 1 and 2.
In the second 30 minutes, she copies tape 1 side B and tape 3 side A (finishing Tape 1).
In the last 30 minutes, she copies tape 2 side B and tape 3 side B.