A man lives on the fifteenth floor of an apartment building. Every morning he takes the elevator down to the lobby and leaves the building. In the evening, he gets into the elevator, and, if there is someone else in the elevator, or if it was raining that day, he goes back to his floor directly. Otherwise, he goes to the tenth floor and walks up five flights of stairs to his apartment. Can you explain why he does this?

Find the last number in the series below:

voN luJ yaM raM ---

What's the only room from which no one can enter or leave

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

I know a nine-letter word having only one vowel.
Do you ?

Considering the below equation:

V + II - VI = 10
IV - X + VIII = 20
IV - VII + VI = 30

Then, I + II + III = ?

Move four matchsticks to the below square to form three squares?

In this image, you can see three almost identical Doraemon images. Can you spot the odd one out from them?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

We have four gears with below features=> Both Gear A and D has 60 teeth=> Gear B has 40 teeth=> Gear C has 20 teeth=> Every two minutes, Gear B makes 25 full turns.What is the relative speed of Gear A and Gear B?