How can you tell a raw egg from a hard-boiled egg?

Teacher ask the student

'Why are you standing on that chair in music class ?'.

what did student replied ?

Spelt forwards I’m what you do every day, spelled backwards I’m something you hate. What am I?

A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

What you cannot hold but it is yours?

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

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?

When monkey rotate the gear, which mark will be hit 1 or 2 ?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

What is the difference between a jeweller and a jailer?