It’s great to keep checking your speed quite often even when we feel we are comfortable with a particular variety of questions. What matters actually is not that you know how to solve a particular variety but, in how much time you could solve it. Because even knowing or being good at a particular variety does not ensure that one would be able to solve the same in the prescribed time limit. These questions form a base for us to check ourselves and prepare for the upcoming exams accordingly.
Solve, Speed up, and succeed!
All the Best! 🙂