Question: What is more useful when it is broken?

Question: Mary was working in a chemistry lab with a mixture of chemicals that was 90% water and weighed 20 pounds. After returning to the lab from a weekend break, she calculated the mixture was now 50% water. How much does the mixture now weigh? For purposes of this puzzle, assume the non-water part of the mixture was not affected by evaporation.

Question: A sign on the barber's door says "I shave only those who do not shave themselves". Does the barber shave himself?

Question: The king dies and two men, the true heir and an impostor, both claim to be his long-lost son. Both fit the description of the rightful heir: about the right age, height, coloring and general appearance. Finally, one of the elders proposes a test to identify the true heir. One man agrees to the test while the other flatly re-fuses. The one who agreed is immediately sent on his way, and the one who re-fused is correctly identified as the rightful heir.
Can you figure out why?

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Question: A psychologist goes to a village in Africa and decides to compare foot size to intelligence. He notes that in general, as foot size increases, so does intelligence. How can this be?

Question: A wife and her husband were driving in their car on the highway. All of a sudden, they ran out of gas. So the husband said to the wife, "Now, you stay here. I will go down the highway to the nearest gas station, and I will be about 1 hour. Just listen to the radio and read some books, and remember to lock all the windows and doors. I will leave the keys with you." So, off the husband went, and the wife first locked ALL the windows and doors. Next, she turned on the radio, and this is what she heard on the news report:
"THERE IS A MURDERER ON THE LOOSE. HE WAS LAST SEEN ON THE HIGHWAY, WEARING ALL BLACK, ABOUT 5 FOOT 11 INCHES. PLEASE, BE AWARE AND CONTACT THE POLICE IMMEDIATELY." The wife got very scared. She turned off the radio and double checked the locked doors. Then she saw the murderer, only a couple feet away from the car. An hour later, the husband returned to his car. Inside the car, his wife was DEAD, she had been murdered. All the windows were still locked, and the doors. No windows were broken, and the car was in PERFECT condition. No scratches or anything, it was the same way as when he left it. How did the murderer kill the wife?

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Question: I have no voice and yet I speak to you, I tell of all things in the world that people do. I have leaves, but I am not a tree, I have pages, but I am not a bride or royalty. I have a spine and hinges, but I am not a man or a door, I have told you all, I cannot tell you more. What am I?

Question: I am that which is hunted, and this panes me. Do you dig, Stone?
What am I?

Question: There are two bodies on the floor. They are surrounded by water and broken glass. How did they die?

Question: My life can be measured in hours,
I serve by being devoured.
Thin, I am quick
Fat, I am slow
Wind is my foe.