This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

Can you find out the missing number in the grid?

Birbal was jester, counsellor, and fool to the great Moghul emperor, Akbar.
The villagers loved to talk of Birbal's wisdom and cleverness,
and the emperor loved to try to outsmart him.
One day Akbar (emperor) drew a line across the floor.
"Birbal," he ordered, "you must make this line shorter, but you cannot erase any bit of it."
Everyone present thought the emperor had finally outsmarted Birbal.
It was clearly an impossible task.
Yet within moments the emperor and everyone else present had to agree that Birbal had made the line shorter without erasing any of it.
How could this be?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?

Why Wine Glass Stem is so long?

Which city is three-fifths chick two third cat and 50% goat?

Can you name any English verb that becomes its past tense by simply rearranging the alphabets ?

Can you find out the total number of triangles in the given figure?

Which alphabet is a part of our body?