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

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

Do You See It?

When it is alive we sing, when it is dead we clap our hands. What is it?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?

The captain of a ship is telling you an interesting story and then poses a question. He says, “I have travelled the oceans far and wide. One time, two of my sailors were standing on opposite sides of the ship. One was looking west and the other one east. And at the same time, they could see each other clearly. Can you tell me how that was possible?”

In the image below, you can see two glasses and two matchsticks.You need to move four matchsticks in such a manner that the crosses come inside the glasses. Note: you cannot move the crossed.

A newspaper is supposed to have 60 pages, but pages 24 and 41 are missing.
Which other pages won't be there?

How many bricks does it take to complete a building that is 15 feet wide, 30 feet deep, and 12 feet tall made of brick?