There is no steam. It’s an electric train.

Because Oct 31 represents the octal (base 8) number 31, which, when converted to decimal, is 25. Dec 25 is short for Decimal 25, thus the two are equal.

The most popular answer for this teaser is ‘today’. Of course this only works if you’re reading it on that particular date or if the date is not specified. Another option is to respond literally with ‘a date’. Lastly, certain dates could be squeezed into letters using Roman numerals if you abbreviate the year to 2 numerals. For example, January 20th, 2011 would be I XX XI.

99 9/9 = 100

Milton sadly suffers from alopecia, more commonly known as baldness. The old coot was as bald as a ping pong ball, leaving not a single hair on his head to get wet.