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?

You are given four tennis balls and asked to arrange those balls in a manner that the distance between each one of them is exactly equal. How will you do it?

Why Wine Glass Stem is so long?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

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?

A deaf and mute man goes to the train station. Tickets for the train are 50 cents each. The man goes to the ticket booth and hands the man inside just a dollar. The man in the booth hands him two tickets.

How did the man in the booth know to give him two tickets without even looking at him?

Give it food and it will live; give it water and it will die.

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?