Sum of products in every second column

**galm** · 01-08-2010, 05:28 AM

I am sure this is simple but I have not found out the solution anyway....

Example:
A B C D E F G
1 2 100 0 0 2 100 400
2 2 100 10 50 0 0 700
3 2 100 0 0 2 200 600

Columns A, C and E are number of items on each "unit".
Columns B, D and F are the number of "units" (e.g. to produce).
Column G are the resulting number of items that need to be purchased.

So, column G is a sum of products and the formula found below if put in G1 will do the trick.

=A1*B1+C1*D1+E1*F1

What I would like instead is to have a "formula" that allows me to insert new pairs of columns without having to change the formula to include the new column pairs.

Is this doable?

Thanks in advance!

Regards,
/Gunnar

**DonkeyOte** · 01-08-2010, 05:37 AM

Using your file, your formula for I3 would be:

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however - regards:

Originally Posted by galm

What I would like instead is to have a "formula" that allows me to insert new pairs of columns without having to change the formula to include the new column pairs.

is unclear...depending on how & where the new columns are inserted the formula you use c(w)ould adapt accordingly.