What do you answer even though it never asks you questions?

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

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

If 2 workers can complete painting 2 walls in exactly 2 hours.

How many workers would be needed to paint 18 walls in 6 hours?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

How can you drop a raw egg from a height onto a concrete floor without cracking it?

In the image given, you can find several triangles. Can you count them all?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

What does below pictogram mean?

Mr Black, Mr Gray, and Mr White are fighting in a truel. They each get a gun and take turns shooting at each other until only one person is left. Mr Black, who hits his shot 1/3 of the time, gets to shoot first. Mr Gray, who hits his shot 2/3 of the time, gets to shoot next, assuming he is still alive. Mr White, who hits his shot all the time, shoots next, assuming he is also alive. The cycle repeats. If you are Mr Black, where should you shoot first for the highest chance of survival?