asssuming a disk should never get 85% full & assuming you were generating 200 MB per week of new data, at what point would you need to add another hard disk?

Not knowing how big the disk is, it's hard to say.

I need an answer

To determine at what point you would need to add another hard disk, you need to calculate when the current disk will reach 85% of its capacity.

Let's break down the calculations step by step:

Step 1: Calculate the current disk's capacity
Assuming you know the total capacity of the current disk, let's say it's 100 GB (gigabytes). To calculate the maximum allowable capacity (85% full), you need to multiply the total capacity by 0.85:
100 GB * 0.85 = 85 GB

Step 2: Calculate the maximum disk usage before adding another hard disk
Since you are generating 200 MB (megabytes) of new data per week, you need to determine how many weeks it will take for the disk usage to reach 85 GB.

Let's convert the 200 MB per week data generation into GB:
200 MB = 0.2 GB

Now, calculate the number of weeks it would take to reach 85 GB:
85 GB / 0.2 GB per week = 425 weeks

Therefore, it would take approximately 425 weeks to fill up the current disk to 85% of its capacity.

Alternatively, you could convert the number of weeks into years to give you a better sense of when another hard disk might be needed. Assuming there are 52 weeks in a year:
425 weeks / 52 weeks per year ≈ 8.17 years

Based on this calculation, it would take around 8.17 years to reach 85% capacity of the current disk if you continue generating 200 MB per week.

Keep in mind these calculations are based on assumptions and estimates. It's always a good idea to regularly monitor disk usage and adjust accordingly to avoid data loss or system slowdowns.