You have two rectangular wires.

Both of them have property that when you light the fire from one end , it will take 60 minutes to get completely burn.

However, they do not burn at consistent speed (i.e it might be possible 1st 20% burn in 50 minutes and 80% can burn in 10 minutes).

So how could you measure 45 minutes ?

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?

If we tie a Sheep to one peg, a circled grass is been eaten by the Sheep. If we tie the Sheep to two pegs with a circle on its neck, then an eclipse is eaten out of the grass by the Sheep. If we want an eclipse then we put two pegs and then put a rope in between them and the other end of the rope is tied up on the Sheep's neck.

How should we tie the peg and the Sheep so that a square is eaten out from the garden grass? We only have one Sheep rope and the peg and the rings.

You board a train. The train will have to enter a tunnel soon. You are claustrophobic. Which place is the best for you to sit?

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 live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

Akbar called Birbal and asked him to draw a line on the floor. He asked Birbal to make that line smaller without erasing it. Birbal smiled and did it before Akbar could blink his eyes.

How did he managed to do it?

If 2 workers can complete painting 2 walls in exactly 2 hours.

How many workers would be needed to paint 18 walls in 6 hours?

Can you make the number 24 by utilizing the numbers 1, 3, 4 and 6? You must use one number only one time and you can use mathematical operation symbols anytime anywhere.

What three numbers, none of which is zero, give the same result whether they’re added or multiplied?