I suggest right the opposite.

Coming back to the question and the answers. I have participated in dozens of programming contests, including international ones and team programming contests, and have seen hundreds of assignments, tasks, and multiple choice questions related to programming, maths, algebra, physics, computing etc.

Sorry to say, but the questions in the subject sucks!!!

The reason being is that the precise function which is BETWEEN is used over random data.

Precise answers such as YES and NO by definition are not right (with rare exceptions), NOT DEFINED is the only correct answer in this case.

If the question creator did not want to have this discussion, he should not have used random figures, as I mentioned. He should have used a gradient or other predictable function such as SIN, COS, MOD etc.

ps: I am sure there would be many people thinking like me, they just either don't read this forum or save their (and their company) time.