81 x 9 = 801. What must you do to make the this equation true?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

A four-digit number (not beginning with 0) can be represented by ABCD. There is one number such that ABCD=A^B*C^D, where A^B means A raised to the B power. Can you find it?

What has hands, but can’t clap?

Do you know who was buried in John's tomb?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

If 1+9+8=1, what is 2+8+9?

Can you find the largest Three-digit number whose sum is 14 and whose square is less than 5,00,000?

We are a group of eight brothers. We consider the weak, yet we protect the king in every battle. If we move ahead, we never turn back. Who are we?

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?