Dumb questions?

so one of the quizzes at the end of a section had this

Which tool is yields the fastest and most affordable method to cut PVC Pipe?


That's correct, a chop saw is the fastest, but the least economical.

This is obviously wrong and very confusing, so the 50 trillion dollar question is - was this done by design, was it a mistake, and where was the error inserted? I have done expensive microsoft exams that were deliberately broken in this manner...