Real life probability problem

#1
So I'm wondering if someone can solve this problem for me. Some work was done in our kitchen yesterday and the fridge had to be moved. I noticed some pretty bad scratches on the wood floor that were clearly from the fridge. The fridge hadn't been moved for 39 days prior. So what is the probability that the scratches had gone unnoticed for 39 days, given that I noticed the scratches one day after the recent work was done? Thank you