Critical Thinking Puzzles

if a 0.1mm paper is folded 100 times then what will be the thickness of it after 100 foldings?

Would anyone know the shortest sentence in the English language that has every letter of the alphabet?

How many times are the hands of a clock at right angle in a day?

You have three jars that hold max 19, 13 and 7 liters of water respectively. 13 and 7 litre jars are full of water and 19 litre jar is empty...

There is a safe with a 5 digit number as the key. The 4th digit is 4 greater than the second digit, while the 3rd digit is 3 less than the 2...

Imagine a 3x3x3 wooden cube. How many cuts do we need to break it into 27 1x1x1 cubes?

Two boys want to cross a river. The only way to get to the other side is by boat, but that boat can only take one boy at a time. The boat ca...