Three travelers register at a hotel and are told that their rooms will cost $10 each so they pay $30. Later the clerk realizes that he made a mistake and should have only charged them $25. He gives a bellboy $5 to return to them but the bellboy is dishonest and gives them each only $1, keeping $2 for himself. So the men actually spent $27 and the bellboy kept $2. What happened to the other dollar of the original $30?
There is no missing dollar from the original $30 because after getting $1 back, the three travelers had paid a total of $27 for their room ($9 each), not $30. Out of that $27, the hotel has $25 and the clerk kept the remaining $2. If you still want to work from the original $30, the travelers have $3, the hotel has $25 and the bellboy has $2. The misleading part is adding the bellboy’s $2 to the $27, when in fact it should be subtracted.
My family sings Christmas carols at the hospital where my wife works. We do this every year and since we started, have not missed a single year. The next time we do this will be the 18th consecutive Christmas. My 15 year old daughter has been every time.
She was born in March 1999 so the first year she came was December 1999 (before her 1st birthday). Her first time was when she was 0, second time when she was 1, third time when she was 2, etc…
Now that she is 15, she has been 16 times. Oh and of course she was also present in December 1998 in her mum’s belly, due to be born the next March.
So, a total of 17 times and next time will be the 18th.
Thanks to Michael for submitting this real-life brain teaser about his family.
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.
What must be in the oven yet can not be baked? Grows in the heat yet shuns the light of day? What sinks in water but rises with air? Looks like sand, but is fine as hair?
An 18-wheeler is crossing a 4 kilometer bridge that can only support 10,000 kilograms and that’s exactly how much the rig weighs. Halfway across the bridge a 30 gram sparrow lands on the cab, but the bridge doesn’t collapse. Why not?
Since the bridge is 4 kilometers long, the halfway point would be 2 kilometers. The 18-wheeler would have used much more than 30g of fuel to drive 2 kilometers.