In which direction should the missing arrow point?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

In a box, there is a jumble of 7 red balls, 6 blue balls, 5 green balls, and 4 yellow balls. What is the minimum number of balls, will you have to pick up so that you have at least 4 balls of the same colour?

What numbers should go on the bottom line?
3 6 9 15
8 2 10 12
11 8 19 27
19 10 29 39
? ? ? ?

An artist while painting a scenic beauty, decides to paint three layers of blue colour on the sky.

Which layer will go on the first?

In the picture, you can see a chess board. On the top left position, the K marks a knight. Now, can you move the knight in a manner that after 63 moves, the knight has been placed at all the squares exactly once excluding the starting square?

This is a picture puzzle. You have to guess the name of the movie that can be related to the picture.

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?