Excel's Formula - sisman

Yet another way to perform this count is to use an array formula:
Chapter 7: Counting and Summing Techniques 191
{=SUM((Month=”January”)*(SalesRep=”Brooks”)*(Amount>1000))}
Using Or criteria
To count cells by using an Or criterion, you can sometimes use multiple COUNTIF functions. The
following formula, for example, counts the number of sales made in January or February:
=COUNTIF(Month,”January”)+COUNTIF(Month,”February”)
You can also use the COUNTIF function in an array formula. The following array formula, for
example, returns the same result as the previous formula:
{=SUM(COUNTIF(Month,{“January”,”February”}))}
But if you base your Or criteria on cells other than the cells being counted, the COUNTIF function
won’t work. (Refer to Figure 7-2.) Suppose that you want to count the number of sales that meet
the following criteria:
Month is January, or
SalesRep is Brooks, or
Amount is greater than 1,000
If you attempt to create a formula that uses COUNTIF, some double counting will occur. The solution
is to use an array formula like this:
{=SUM(IF((Month=”January”)+(SalesRep=”Brooks”)+(Amount>1000),1))}
Combining And and Or criteria
In some cases, you may need to combine And and Or criteria when counting. For example, perhaps
you want to count sales that meet the following criteria:
Month is January, and
SalesRep is Brooks, or SalesRep is Cook
You can add two COUNTIFS functions to get the desired result:
=COUNTIFS(Month,”January”,SalesRep,”Brooks”)+
COUNTIFS(Month,”January”,SalesRep,”Cook”)