Best riddles for teens

logicsimplecleanclever

You have two jugs, one that holds exactly 3 gallons, and one that holds exactly 5 gallons. Using just these two jugs and a fire hose, how can you measure out exactly 4 gallons of water?
Fill the 5-gallon jug to the top, and then pour it into the 3-gallon jug until the 3-gallon jug is full. You now have 2 gallons remaining in the 5-gallon jug. Pour out the 3-gallon jug, and then pour the 2 gallons from the 5-gallon jug into the 3-gallon jug. Finally, fill the 5-gallon jug to the top and pour it into the 3-gallon jug until it's full. Since there was only space left for 1 more gallon in the 3-gallon jug, you now have exactly 4 gallons in the 5-gallon jug.
80.14 %
48 votes
logicmathsimpleclean

I know a number which when multiplied by multiple of 9 i.e 9 18 27 36 45 ... The output consist of number containing only one digit. Can you identify the number?
12345679 12345679 × 9 = 111111111 (only 1s) 12345679 × 18 = 222222222 (only 2s) 12345679 × 27 = 333333333 (only 3s) 12345679 × 36 = 444444444 (only 4s) 12345679 × 45 = 555555555 (only 5s)
80.14 %
48 votes
cleansimple

I am in a land where thirty men and two women were dressed in classic black and white dress. They began to fight as soon as any of them moves. Where am I ?
In a Chess board.
80.14 %
48 votes
logictrickyclever

If a farmer has 5 haystacks in one field and 4 haystacks in the other field, how many haystacks would he have if he combined them all in the center field?
One. If he combines all of his haystacks, they all become one big stack.
80.14 %
48 votes
logicstorytricky

Two Japanese people who have never seen each other meet at the New York Japanese Embassy. They decide to have drinks together at a nearby bar. One of them is the father of the other one's son. How is this possible?
The Japanese are husband and wife and both blind since birth.
80.14 %
48 votes
logiccleansimpleclever

A man needs to send important documents to his friend across the country. He buys a suitcase to put the documents in, but he has a problem: the mail system in his country is very corrupt, and he knows that if he doesn't lock the suitcase, it will be opened by the post office and his documents will be stolen before they reach his friend. There are lock stores across the country that sell locks with keys. The only problem is that if he locks the suitcase, he has no way to send the key to his friend so that the friend will be able to open the lock: if he doesn't send the key, then the friend can't open the lock, and if he puts the key in the suitcase, then the friend won't be able to get to the key. The suitcase is designed so that any number of locks can be put on it, but the man figures that putting more than one lock on the suitcase will only compound the problem. After a few days, however, he figures out how to safely send the documents. He calls his friend who he's sending the documents to and explains the plan. What is the man's plan?
The plan is this: 1. The man will put a lock on the suitcase, keep the key, and send the suitcase to his friend. 2. The friend will then put his own lock on the suitcase as well, keep the key to that lock, and send the suitcase back to the man. 3. The man will use his key to remove his lock from the suitcase, and send it back to the friend. 4. The friend will remove his own lock from the suitcase and get to the documents. Search: Man-in-the-middle attack
80.14 %
48 votes
simplelogictricky

Two sentries were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone was approached from the South. Suddenly one of them said to the other, "Why are you smiling?" How did he know that his companion was smiling?
Although the guards were looking in opposite directions, they were not back to back. They were facing each other.
80.14 %
48 votes