Problem:

Column B contains a list of letters which are codes for the hours worked on each of the days listed in column A.
\"N\" indicates a 9 hour day, \"H\" indicates a 4 hour day and \"V\" indicates no hours were worked that day.
We want to calculate the total number of hours worked during the week.

Solution:

Use the COUNTIF function as shown in the following Formula:
=COUNTIF(B2:B8,\"N\")*9+COUNTIF(B2:B8,\"H\")*4