The time one needs to spend on a given assignment could also vary by individual abilities and their nature/density/rigor.
For some of the readings I’ve had in intro/intermediate undergrad classes in my core academic fields of interest, I had no issues reading them without skimming in around 2-3 hours straight through while being able to retain most of the information. In contrast, I had one classmate who could do the same degree of justice to the same readings in 45 minutes-1.5 hours and several other classmates…including older classmates 2-3 classes ahead who’d struggle to do the same degree of justice to those readings while taking twice as long/more or never finish what I’d consider a light-moderate reading college-level assignment.
And this wide spectrum of time required to complete the same given assignment was further underscored when I tutored several students who happened to be taking the same class and doing the exact same assignment with the same Prof.