I remember during tests I'd get stuck at the hardest problems and stubbornly solve them only to run out of time on the easy questions and haphazardly answer the

I remember during tests I'd get stuck at the hardest problems and stubbornly solve them only to run out of time on the easy questions and haphazardly answer them until the "pen up" was announced. At some point a teacher taught us how to maximize our scores resembling the strategy you mention and yes, it did help. We weren't smarter by any means, but had a better strategy to taking tests.