A swan sits at the center of a perfectly circular lake. At an edge of the lake stands a ravenous monster waiting to devour the swan. The monster can not enter the water, but it will run around the circumference of the lake to try to catch the swan as soon as it reaches the shore. The monster moves at 4 times the speed of the swan, and it will always move in the direction along the shore that brings it closer to the swan the quickest. Both the swan and the the monster can change directions in an instant.
The swan knows that if it can reach the lake's shore without the monster right on top of it, it can instantly escape into the surrounding forest.

How can the swan successfully escape?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

There is a square piece of paper with a hole that is denoted by the circle on the top right side in the given picture. You have to cut the paper in a manner that it forms two and only two separate pieces of paper and then rearrange the pieces in a manner that the holes come in the centre of the paper.

Can you count the number of quadrilaterals in the picture below?

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

Make a sentence consisting of three words that have the whole alphabet.

A man was driving a black truck. His lights were not on. The moon was not out. A lady was crossing the street. How did the man see her?