This was Gollum's final riddle from The Hobbit:
"This thing all things devours;
Bird, beasts, trees, flowers;
Gnaws iron, bites steel;
Grinds hard stones to meal;
Slay king, ruins town,
and beats a mountain down."
There is a creature which could double its size every day. So, if the creature is put in a tank then it will fill the tank in 10 days.
How many days would it take for the creature to fill a half and how many days to fill a quarter of the tank?
You're sitting in a car. The car has helium balloons tied to its floor. The windows in the car are closed and locked and the Air conditioner isn't working.
What will happen to the balloons when you press on the gas?
Will they move forward, stay in place, move backwards...?
The answer is they will move forwards.
Because helium is lighter than air, it will go where air isn't. When the car is pushed forward the air moves backwards, so the helium balloons will move to where the air is not - forward.
A magician is standing on a concrete floor holding a raw egg with his hand outstretched.
Without the aid of any other objects, he is able to drop the egg 2 feet without breaking its shell.
How did he do it?
If we look at the green bar we see that its real height is 2/3 of its shadow. So that means we need to find 2 shadows length for the red bar, the uninterruped part and the one on the wall. Since we now know the formula for the floor shadow - real height is 2/3 of it - meaning the part that makes that shadow is 4 meters long. Then we have to add the part on the wall which is straight up, it has no formula so we just add those 4 meters on the wall to the 4 meters we got from multiplying 2/3 by 6 meters and we have 4 meters + 4 meters = 8 meterss
Einstein's Riddle: The Pet Fish
There are five houses in a row. Each house is painted a different color and has a person of a different nationality living in it. Each person drinks a different beverage, smokes a different type of cigar, and owns a different animal as a pet.
Using these 15 clues, which person owns the pet fish?
The Brit lives in the red house.
The Swede has a pet dog.
The Dane drinks tea.
The green house is directly to the left of the white house.
The person in the green house drinks coffee.
The person who smokes Pall Mall has a pet bird.
The person in the yellow house smokes Dunhill cigars.
The person in the center house drinks milk.
The Norwegian lives in the first house.
The person who smokes Blends lives next to the person with the pet cat.
The person with the pet horse lives next to the one who smokes Dunhill.
The person who smokes BlueMaster drinks beer.
The German smokes Prince.
The Norwegian lives next to the blue house.
The person who smokes Blends has a neighbor who drinks water.