When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

John said, "If yesterday was tomorrow, today would be Friday."

When did John make this statement?

There’s a one-story house in which everything is yellow. Yellow walls, yellow doors, yellow furniture. What colour are the stairs?

Let's play a word game. Following are some meaningless words that can be completed by adding random letters on either side of the word.

For example, the word "rdo" can be formed into "pardon".

Using the same technique, can you complete the given words?
ecalc
airb
rinci
tibac
uidel
gorit
igna
eyho

There is a square piece of paper with a hole that is denoted by the circle on the top right side in the given picture. You have to cut the paper in a manner that it forms two and only two separate pieces of paper and then rearrange the pieces in a manner that the holes come in the centre of the paper.

You bought me for dinner but never eat me. What am I?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

How many times do a clock's hands overlap in a day ?

Two boys wish to cross a river. The only way to get to the other side is by boat, but that boat can only take one boy at a time. The boat cannot return on its own, there are no ropes or similar tricks, yet both boys manage to cross using the boat.

How?

What has hands, but can’t clap?