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.
A man gets ready for bed at 9:45 pm. He makes himself a drink, then turns off the TV and the lights. The night was windy and there was a major storm. The next day he discovers he was the cause of seven deaths. How is this possible?
He lived in a lighthouse as lighthouse keeper. He turned off all the lights by accident, so a ship with 7 passengers couldn’t negotiate the rocky shores. One would think the light switches in a lighthouse would be more clearly marked.
Last winter I found myself locked out of my house because I couldn’t remember the 5-digit code to open the garage door. I used the following facts to get inside.
1. The second and third digits add up to 9.
2. The first digit is equal to the second digit cubed.
3. The sum of the third and fifth digits is the smallest number with exactly five divisors.
4. The fourth digit is equal to 6 times the second-to-last digit.
5. None of the digits repeat.
If we label each digit a, b, c, d and e, we get the following equations.
1. b + c = 9
2. a = b3
3. c + e = 16 (since 16 is the smallest number with five divisors – 1, 2, 4, 8 and 16).
4. d = 6 * d (The fourth and second-to-last digits are the same number, meaning d must be zero to satisfy the equation)
5. b must be zero, one or two (b can’t be three because that makes a=27, which isn’t a single digit). Zero and one result in duplicate digits (00907 and 11808 respectively) so the only remaining value for b is 2, giving us 82709 and warmth.