There are nine dots in the picture that has been attached with this question. Can you join all the dots by drawing four straight lines without picking up your pen?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

Solve the riddle below:

If a Chicken says, 'All chickens are liars" is the chicken telling the truth?

Find the missing letter in the last circle logically in the given below picture.

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

What Adam and Eve do not have but the rest of the people have?

An old Woman left INR 33,333 to be divided equally among two fathers and two sons and each was to receive INR 11,111.
How was this possible?

An equation has been laid down using a few matchsticks. However, as you can see, the equation is not correct. Can you correct the equation if you are allowed to add or remove 5 matchsticks?

2, 3, 5, 9, 17, _ What is the next number in the sequence?