2018 OG Practice Questions

Hello, I signed up a while back to receive the emails, and more than 60 days have passed since then (mixture of procrastination and starting a new job). Back then I completed about a week's worth of work. I have now decided to carry on, but I have bought the 2018 OG book, as earlier I was just using...

I don't know if necroing is allowed on Beat The GMAT, feel free to delete my post and I'll make another one if required. This explanation isn't sufficient to me. It doesn't address the OP's question: what in the formulation of the question prevents a cone with a base of radius r and a height of h wh...