Though in most reference books and a useful thing to know you
will NOT be examined on multi-sector PSR/PET questions in Flight Planning.
Just make sure given the parameters and reading the question
use the correct formula for the appropriate problem.
Braking Coefs have been around IFR comms more or less since JAA started, but the coef is in whole numbers.
Eg. 25 not 0.25 for Poor.