Answer:
1. Total time for the first two batches (T1) = 2 * 30 minutes = 60 minutes.
2. Total time for the remaining batches (T2) = (B - 2) * 20 minutes.
3. Number of batches needed to make 8 dozen cookies (B) = 8 dozen / 1 dozen per batch = 8 batches.
4. Substitute B into the equation for T2: T2 = (8 - 2) * 20 minutes = 6 * 20 minutes = 120 minutes.
5. Total time (in minutes) = T1 + T2 = 60 minutes + 120 minutes = 180 minutes.
6. Convert the total time to hours: 180 minutes / 60 minutes per hour = 3 hours.
So, it will take you 3 hours to make all eight dozen cookies at the given pace.