In the scenario it says:
"The active users per day are 70 percent, out of which 30 percent are involved in common operations and 20 percent in complex operations. The number of business hours is 12, and the peak factor is 4."
I think what was meant is:
"The active users per day are 70 percent, out of which 30 common operations and 20 complex operations are performed each per active user, per day. The number of business hours is 12, and the peak factor is 4."
I can find no other clues in the scenario to asses the number of common and complex operations per active user per day, which is a required variable for the formulae. This number also sounds like a realistic average for typical WSS 3.0 users.