What has 13 hearts but no other organs?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

In the image below, can you find the value of an angle(y)

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

Can you find the odd number in the following?

2716, 4135, 5321 and 7145

P is the father of Q and S is the son of R. T is the brother of P and has a daughter U. If R is the sister of P, then what is the relation between U, Q and S?

Find the hidden tiger in the given optical illusion ?

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

What number divided by 4 is the same as that number minus 4?