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?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

In a box, there is a jumble of 7 red balls, 6 blue balls, 5 green balls, and 4 yellow balls. What is the minimum number of balls, will you have to pick up so that you have at least 4 balls of the same colour?

Can you Find and name the hidden bird in the picture below ?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

I am dry when I go inside, but wet when I am pulled outside.
The longer I am inside, the stronger I get
When I am completely out, I am wet and I literally sag
Who am I?

You knock a Table over in the library, and suddenly 20 eyes are looking at you.

Can you count the number of triangles in the given figure?

Alex is stranded on an island covered in forest.
One day, when the wind is blowing from the west, lightning strikes the west end of the island and sets fire to the forest. The fire is very violent, burning everything in its path, and without intervention the fire will burn the whole island, killing the man in the process.

There are cliffs around the island, so he cannot jump off.

How can the Alex survive the fire? (There are no buckets or any other means to put out the fire)

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99