Applied at The Guardian for Editorial Assistant

I recently received a job offer that I'm starting to think might be a scam. An email came through from someone named William Anderson, claiming to be with The Guardian, for an editorial assistant position. Instead of the typical interview process, he sent me a PDF with questions to answer at my convenience. This struck me as odd since I’ve never encountered a job application like this before. What raised my suspicions even more was the pay he mentioned. He offered $20 to $30 an hour, which translates to less than $62,000 a year. That just doesn’t seem right to me. I’m reaching out to see if anyone else has had a similar experience or if they have any advice on how to proceed. Should I respond, or is this a red flag?