Help to calculate human resources

Question

I need to calculate the number of people I would need to complete a task.

So I have to prepare 2000 items in 4 hours and I know that on avg one person can prepare roughly 30 items per hour, also I know that each hour I receive additional 400 items to prepare.

How to calculate the number of people I need to process the total?

Thanks

Answer 1

There are $2000+400(4)=3600$ items to prepare in total. If a person can prepare $30$ items,the items prepared by that indivisible in $4$ hours is $120$. So $3600=120n$ Is how many people you need which is $n=30$.