What has no start, end, or centre?

Name the three-letter word that can complete the below words:

A) L O _ _ _ E
B) E D U _ _ _ E
C) _ _ _ E R
D) _ _ _ T L E

If 2 workers can complete painting 2 walls in exactly 2 hours.

How many workers would be needed to paint 18 walls in 6 hours?

What demands an answer, but asks no questions

If it took eight men ten hours to build a wall, how long would it take four men to build it?

When we see 2 but call 10?

What is the riddle which can be asked all day with a different correct answer each time.

Imagine you are in a room with no windows or doors. How will you get out?

What does does this rebus picture means ?

Open a Laptop which is password protected. Hint for the password is given as below:

1 mobile 3 books 2 Boards 1 night 4 balls 2 lighters 1 ghost 1 hat 3 watches