If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

Identify the hidden meaning behind this picture?

If "P" means "-", "Q" means "/", "R" means "+", and "S" means "*" then find the value of the following:

21 Q 7 R 9 S 10 P 13

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

Buy me, smell me or deliver me, I do not change.

Who am I?

There are 100 bulbs in a room. 100 strangers have been accumulated in the adjacent room. The first one goes and lights up every bulb. The second one goes and switches off all the even-numbered bulbs - second, fourth, sixth... and so on. The third one goes and reverses the current position of every third bulb (third, sixth, ninth? and so on.) i.e. if the bulb is lit, he switches it off and if the bulb is off, he switches it on. All the 100 strangers progress similarly.

After the last person has done what he wanted, which bulbs will be lit and which ones will be switched off?

Why do you find that most of the buildings are deprived of the 13th floor?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

What is greater than gold but cannot be bought. it can never be sold and can earn if its sought. though it can be broken, it can still be fixed. for by birth it can't start nor by death it is ended.what am i?