I'm trying to create a mathematical operation that help me to resolve this scenario.
I have a list of "limits" as show below:
0---4---8---12... (n + 4)
Suppose that we have a software that "read" a number, an it determines what is the previous "step limit". For example:
Given | Previous limit step 3 | 1 (the limit would be 0) 4 | 2 (the limit would be 4) 7 | 2 (the limit would be 4) 9 | 3 (the limit would be 8)
What I need to do is trying to get the previous limit in question, as show below:
Given | Previous limit 3 | 0 4 | 4 7 | 4 9 | 8
I have two days dealing with a formula to get it, but no good results.