Best riddles

logicmystery

Lost jewelry

A couple went on holiday for three weeks. They carefully locked their house, and had a neighbor check on the place while they were gone. When they returned, the wife was distressed to lean that because of a power failure she had lost all her fine jewelry. She had hidden the jewelry in what she thought was a very safe place. She was not robbed. Her jewelry was lost by accident. Why?
In this true incident, the wife had hidden her best jewelry inside her freezer in a bag among all the frozen food. Because of a general power failure the freezer had gone off. A friendly neighbour (who had a key in order to water the plants) had tried to be helpful by throwing out all the bad food - and with it went the jewelry.
90.04 %
42 votes

interviewlogicmath

King and Wind Bottles

A bad king has a cellar of 1000 bottles of delightful and very expensive wine. A neighboring queen plots to kill the bad king and sends a servant to poison the wine. Fortunately (or say unfortunately) the bad king’s guards catch the servant after he has only poisoned one bottle. Alas, the guards don’t know which bottle but know that the poison is so strong that even if diluted 100,000 times it would still kill the king. Furthermore, it takes one month to have an effect. The bad king decides he will get some of the prisoners in his vast dungeons to drink the wine. Being a clever bad king he knows he needs to murder no more than 10 prisoners – believing he can fob off such a low death rate – and will still be able to drink the rest of the wine (999 bottles) at his anniversary party in 5 weeks time. Explain what is in mind of the king, how will he be able to do so?
Think in terms of binary numbers. (now don’t read the solution, give a try). Number the bottles 1 to 1000 and write the number in binary format. bottle 1 = 0000000001 (10 digit binary) bottle 2 = 0000000010 bottle 500 = 0111110100 bottle 1000 = 1111101000 Now take 10 prisoners and number them 1 to 10, now let prisoner 1 take a sip from every bottle that has a 1 in its least significant bit. Let prisoner 10 take a sip from every bottle with a 1 in its most significant bit. etc. prisoner = 10 9 8 7 6 5 4 3 2 1 bottle 924 = 1 1 1 0 0 1 1 1 0 0 For instance, bottle no. 924 would be sipped by 10,9,8,5,4 and 3. That way if bottle no. 924 was the poisoned one, only those prisoners would die. After four weeks, line the prisoners up in their bit order and read each living prisoner as a 0 bit and each dead prisoner as a 1 bit. The number that you get is the bottle of wine that was poisoned. 1000 is less than 1024 (2^10). If there were 1024 or more bottles of wine it would take more than 10 prisoners.
90.04 %
42 votes

cleanlogicmathshort

Number one

How do you make the number one disappear by adding to it?
Add the letter 'G' and it becomes Gone.
89.96 %
57 votes

cleanshort

Sailors travelling the sea

We travelled the sea far and wide. At one time, two of my sailors were standing on opposite sides of the ship. One was looking west and the other one east. And at the same time, they could see each other clearly. How can that be possible?
The sailors had their backs against either ends of the ship.
89.92 %
24 votes

cleanlogicmath

Take 2 from 5

How can you take 2 from 5 and leave 4?
F I V E. Remove the 2 letters F and E from five and you have IV.
89.81 %
41 votes

logicmathshort

10 + 4 = 2

Can you make 10 plus 4 = 2?
Yes. 10 o'clock + 4 hours = 2 o'clock.
89.58 %
40 votes