If eleven plus two equals one, what does nine plus five equal?

Can you find the thief by just looking at the picture below?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

What is the below Rebus indicate?

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

On a certain day, John celebrated his birthday. Two days later, his older twin brother Jacob celebrated his birthday.

Is this even possible? How can it be?

The more you take me, the more you leave me behind.
Who Am I?

Name the three-letter word that can complete the below words?

A) L O _ _ _ E
B) E D U _ _ _ E
C) _ _ _ E R
D) _ _ _ T L E