What will you call your mother's brother's brother-in-law?

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?

The answer I give is yes, but what I mean is no. What was the question?

Imagine you are in a room with no windows or doors. How will you get out?

A 3 digit number is such that it's unit digit is equal to the product of the other two digits which are prime. Also, the difference between it's reverse and itself is 396.

What is the sum of the three digits?

Can you find out the remainder when 3^300 is divided by 5?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

Find The Missing Number In the Sequence.
6 25 64 ? 32 1

Find the Goldfish below the given Image.

It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?