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

Three people check into a hotel. They pay $60 for the rent of the room. After they check-in, the manager realize that the rent for the room is $55. So, he gives $5 to the bellboy and asks him to give it to them. The bellboy thinks that it will be difficult for the three people to share $5 among them and seeking the personal benefit, he pockets $2 and gives the remaining $3 to them.

Now, each person paid $20 and got back $1. In this manner, each of them paid just $19 which totals to the amount of $57. The bellboy has $2 with him and adding them, we get $59. So where is the remaining $1?

In a mathematical quiz, you are asked the following question:

Use three 9s in a mathematical expression without dividing or multiplying to form the number one.

Can you answer the question?

What can go up a chimney down, but can’t go down a chimney up?

On a charity event in Russia, Murray beat Djokovic by winning six games and losing three games.
Note: There is a total of 5 service breaks(one who serve lost the game).
Who served first, Djokovic or Murray?

Take one out and scratch my head, I am now black but once was red. What am I?

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?

You throw me out when you want to use me and you take me in when you don't want to use me.

Who Am I?

What is the next number in this series?

4,12,84,3612....

On one occasion, A Boy collects 71 rupees in form of 20 paise and 25 paise. He collects a total of 324 coins.

Can you tell me how many 20-paisa and 25-paisa he got?