Which Number is the odd one out?

A) 7145
B) 2716
C) 5321
D) 4135

What is the fastest way to double your money?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

A girl has as many brothers as sisters, but each brother has only half as many brothers as sisters. How many brothers and sisters are there in the family?

There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence.

Do you know what word is that?

"That Restaurant always remains crowded. This is the reason why nobody goes there".

Can you find a flaw in this statement?

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?

Complete the following series. It.s very logical:

1, 4, 5, 6, 7, 9, 11, __?

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

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