Cassandra is retiring December $31,2023,$ after many, happy years of employment with

Canadian National Railway Company $($CN$).$ She is fortunate to be part of a Defined Benefit

Pension Plan $($DBPP$).$ Her pension was applicable from the first day of her employment and is

based on years of service and average earnings over the last five years.

a$)$ Calculate Cassandra's annual pension from the DBPP and show the formula calculation: