# Add & Multiply Man-hours - Different results

• Hi i'm trying to calculate the manpower required to get the job done for few tasks.
I have calculated the time for each task and totaled, which amounts to 2:44:00. I have calculated the total man-hour to perform the "total issued" by multiplying the respective cells.
However, sum(D20,D26) (as shown in D28) is different from c27*C13 (as shown in D27)
Am i missing something here, why are the 2 results different.
forum.ozgrid.com/index.php?attachment/35471/

## Files

• Re: Add &amp; Multiply Man-hours - Different results

You will get different results because you are not doing the same thing. However these two formula will give you the same result

=SUM(D20:D26)

=SUMPRODUCT(C6:C12,C20:C26)

• Re: Add &amp; Multiply Man-hours - Different results

Thanks for the formula, it works.(I know it should)
Out of curiosity, C13=sum(c6:c12) and C27=sum(c20:c26)
D20 to D26 each cell is a result of C6*C20, so on and so forth. I thought multiplying c13 with C27 should be the same as adding all the results of multiplying each of the cells.

• Re: Add &amp; Multiply Man-hours - Different results

munirh,

Consider the scenario where all of the times taken (C20:C26) were the same, say 21 minutes. Logically, to get the total time taken, you would multiply the total issued, 6031, by 21 minutes to get the grand total of the time taken (you have issued 6031, each one taking 21 minutes). You wouldn't multiply 6031 by (21 minutes * 7), which is in effect what you are doing.

[COLOR="Purple"]Regards,[/COLOR]
[COLOR="Purple"]Batman.[/COLOR]

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