https://www.gregmat.com/problems/quant?problem=x-lt-y
I think there is a calculation mistake in the solution video.
The answer should be D; I got D too.
Your GPT parsed the equation as 2 \sqrt{x^2 + 2xy + y^2} = 16 when it’s actually 2^{\sqrt{x^2 + 2xy + y^2} }= 16. As such, it got the question wrong. As a sanity check, you could’ve checked the tuple
(x,y) = (3.5, 4.5) to see that it yields 2^{\sqrt{8^2}} = 2^8 \neq 16
I’m not sure how you got D, but please verify an LLM’s output in general. They are not infallible.