Help Creating an Excel Formula

I need to create a formula for Excel that calculates a score based one the number of simultaneous processes a chip can perform in what amount of time. The longer the chip requires to perform a process the greater the penalty should be, but the more processes it can simultaneously the greater the reward should be.

For example:
A chip that takes 1,200 seconds should score 5 points*.
A chip that takes 2,400 seconds should score 11 points.
A chip that takes 3,600 seconds should score 18 points

Similarly:
A chip that can perform 1 simultaneous process should score 5 points
A chip that can perform 2 simultaneous processes should score 11 points
A chip that can perform 3 simultaneous processes should score 18 points

As a result:
A chip that can perform 1 simultaneous process in 1,200 seconds should yield the same score as a chip that can perform 2 simultaneous processes in 2,400 seconds. Which would yield the same score as a chip that can perform 3 simultaneous processes in 3,600 seconds.

How would I write such a formula? Thanks.

*The number of points in the example are not necessarily precise. They’re round numbers intended to demonstrate the exponential growth of the point values.

I could never explain this in words, so I just did it. I’d be happy to send the file to you (why else would I be wasting time at work!). Got an email you prefer?

Thank you very much. davidrossallen [at] gmail [dot] com

Thanks. It’s what I needed and I could even understand what you did.