How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?

How many triangles are there in the picture below?

How can you tell a raw egg from a hard-boiled egg?

John and Jacob are twin brothers. One of them is a liar whereas the other one is a truth-teller.

I called their home number and one of them picked up.
I asked. 'Does John lie?' The person replied with a yes.

Whom did I talk with, John or Jacob?

I hide my treasure in the ground, my tail is big and fluffy. If you spot me in a tree, please don’t call me scruffy. What am I?

Can you tell a 3D object that has just two surfaces?

A brand new Mobile Phone was on sale at 20% as a promotional offer. By what per cent must the Mobile price be increased to sell it at the original price again?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

Who is that with a neck and no head, two arms and no hands? What is it?

A King wants to send the diamond ring to his girlfriend securely. He got multiple locks and their corresponding keys. His girlfriend does not have any keys to these locks and if he sends the key without a lock, the key can be copied in the way. How can King send the ring to his girlfriend securely?