A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

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

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'

Akbar called Birbal and asked him to draw a line on the floor. He asked Birbal to make that line smaller without erasing it. Birbal smiled and did it before Akbar could blink his eyes.

How did he managed to do it?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

There are hundred red gems and hundred blue gems. The blue gems are priceless while the red gems equal wastage. You have two sacks one labeled Heads and the other Tails. You have to distribute the gems as you want in the two sacks. Then a coin will be flipped and you will be asked to pick up a gem randomly from the corresponding sacks.

How will you distribute the gems between the sacks so that the odds of picking a Blue gem are maximum?

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

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?