func evaluateProblem(problemNumber: Int, problemBlock: () -> Int) -> Answer

{

    print("Evaluating problem \(problemNumber)")

    let start = DispatchTime.now() // <<<<< Start time

    let myGuess = problemBlock()

    let end = DispatchTime.now()   // <<<<< End time

    let theAnswer = self.checkAnswer(answerNum: "\(problemNumber)", guess: myGuess)

    let nanoTime = end.uptimeNanoseconds - start.uptimeNanoseconds // <<<<< Difference in nano seconds (UInt64)

    let timeInterval = Double(nanoTime) / 1_000_000_000 // Technically could overflow for long running test

    print("Time to evaluate problem \(problemNumber): \(timeInterval) seconds")

    return theAnswer

}