I have a five and a three-gallon jar. Assuming there is an infinite supply of water, how can I measure one-gallon water?

Can you find out which number multiplied by itself will give the output as 12345678987654321?

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

I make two people out of one. What am I?

Can you identify if it's a murder or a suicide ?

When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?

A prisoner is told: "If you tell a lie, we will hang you and if you tell the truth, we will shoot you." What did the prisoner say to save himself?

Count the number of triangles in the below picture?

If,

20 % 5 = 24

21 % 7 = 33

42 % 6 = 67

Then;

66 % 6 = ?

What English word has three consecutive double letters?