@anarcho-andrei I did take one, many years ago, in high school. The test was far more simple. I am sure it did not have differential equations! But those were much different times. The military has changed from long ago. So have the soldiers.
They are much more sophisticated, intelligent, tech and business savvy nowadays. The ones I interact with can talk foreign politics, philosophy, history, psychology, technology, business, and still hit the center ring at a couple hundred yards. These aren't the grunts from a long time ago. DoD learned that an intelligent soldier was much more effective at achieving in-theater goals. They foster creativity, asymmetrical thinking, game theory, and adaptation. That was the major difference between the centralized control structures of WARSAW, Iraq, etc. and the decentralized operational freedom fostered in most western-nations military.