Final answer:
Blake would practice 105 minutes in 1 week.
Step-by-step explanation:
To find out how many minutes Blake would practice in 1 week, we need to divide the total number of minutes he practices in 4 weeks (420 minutes) by the number of weeks (4). This will give us the average amount of minutes he practices per week.
Therefore, Blake would practice 105 minutes in 1 week.