Cell referencing

[Beginner-Bob]

I have a sales\stock level related problem. Each row on the worksheet
represents a sales day. Column A contains the previous days sales figure, a
list of numbers in the range 1 to 20. Column B is the daily stock level
which starts at 100 (cell B1) and decreases each day by the previous days
sales figure ( the adjacent A cell). Column C is a list of the number of days
it takes to deliver the items when they are re-ordered and will be in the
range 1 to 4 (days). If the stock level (column B) goes below 11 then a
re-order (which is 100 items) is placed and arrives in x number of days where
x is the figure in the adjacent cell in column C.

For example if the stock level falls to < 11 on B5 (day 5), I re-order. As
the number of delivery days (C5) is 4, the re-order (100 items) will be
delivered on day 9 (B9). I want to be able to apply a formula on B5 that
sets B9 equal to 100.

I currently have the formula which I apply to all cells from B2
onwards(example is on B5): =IF((B5-A5)>10,SUM(B5-A5),????). I need to replace
the ????? with a formula or function that puts 100 in cell B9( i.e. cell B5
+4). Can it be done this way or is there some other method? I would value
some help here please.

 

[David Biddulph]

A formula doesn't push a value into a cell other than the cell where you've
put the formula.

Perhaps you want =IF(B5-A5>10,B5-A5,"") in cell B2, and =IF(B5-A5>10,"",100)
in B9?

Note that you don't need SUM(B5-A5), as that is the same as merely B5-A5.