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=SUMIF(A1:B7,1,B2:B7)<br />
<br />
<br />
a &nbsp; &nbsp; &nbsp;b<br />
1 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0<br />
2 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2<br />
3 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0<br />
4 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0<br />
5 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3<br />
6 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<br />
2 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<br />

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=SUMIF(A1:B7,1,B2:B7)


a      b
1      0
2      2
3      0
4      0
5      3
6      1
      
      
      
2      


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sorry its =sumif(A1:A8,1,B2:B7)
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<div class="content wysiwyg-content">
How can I sum a column based on the value of the column next to it. Let me explain:<br />
Column A contains a number, and I want to sum column A1 to A100, but only for those cells where the corresponding B column contains an 'X'. So if B1 contains X then A1 would be part of the sum if B1 does not contain an X then A1 is skipped. And this would be so for each row. 
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How can I sum a column based on the value of the column next to it. Let me explain:
Column A contains a number, and I want to sum column A1 to A100, but only for those cells where the corresponding B column contains an 'X'. So if B1 contains X then A1 would be part of the sum if B1 does not contain an X then A1 is skipped. And this would be so for each row. 

Excel Sum() ?

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