Why do people go to bed?

What number should come in place of the question mark below?

What does this simple rebus mean?

Count the number of triangles in the below picture?

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?

I have branches, but no fruit, trunk or leaves. What am I?

Can it be possible to build a house that has all its four walls facing towards the South?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

Which wheel of car does not rotate when you turn your car right?

Jigsaw captured 100 people and make them stand in a circle and all these people are labelled as Person1, Person2, Person3... Person100. He made them play a crazy game in which Person 1 shot Person 2 and pass the gun to the next person and so on until one stands alive.

Which person will survive in the end?