When I was undergoing a medical examination at the military command, it was necessary to solve special tests to determine the analytical abilities of the candidate for military service, one of which is to solve mathematical expressions. For example, I got this: 2+2x5=?, and to it a set of answers: 45, 20, 50. The answer "12" was not among them.
I called the examiner, and to my surprised reaction that there was no correct answer, she gave a brilliant phrase:
A young man is an army. It has to be solved in an army way. The answer: 20