Replace the question mark with the correct number.

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

John drives to his office at 20km/hr. After reaching the office, he realizes that today is a holiday. He went back at an average speed of 30km/hr. Discounting the time spent in the stoppage what was the average speed of his journey?

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?

What animal walks on four legs in the morning, two legs during the day, and three legs in the evening?

Oedipus, the king of Thebes, figured out the answer to the riddle:

Can you find out which number multiplied by itself will give the output as 12345678987654321?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

What does this simple rebus mean?

Using eight eights and addition only, can you make 1000?

Why did the Girl throw the butter out of the window?