When you were an undergrad, you tackled thousands of problems. Almost always, you were given data and required to find the solution. Life was so straightforward. All you had to do was to find the relevant equation, plug in the numbers, manipulate the equations, and out popped the solution.
Well, by now, you probably realize that real engineering problems are not so clean. You have first to frame the problem, scoop up the data available, collect some more, and then think about the quality of the data. The PE examiners aren’t trying to make you slip, when they supply information you don’t need for PE exam questions and problems. They want to test whether you understand the nature of the problem. They want you to interpret the problem. They want to know whether you really know which relationship addresses the problem. Otherwise, they would be simply testing your algebraic skills, which they assume you already have.