Alpha is Beta's sister.

Gamma is a Beta mother.

Delta is Gamma's father.

Tango is Delta's mother.

Then,

How is Alpha related to Delta?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

Three ants are sitting at the three corners of an equilateral triangle. Each ant starts randomly picks a direction and starts to move along the edge of the triangle. What is the probability that none of the ants collide?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

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.

Which English verb becomes past tense just by rearranging the letters?

Move four matchsticks to the below square to form three squares?

Can you find out who is the kidnapper in below Picture and why, Explain ?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?