The formula extends a formula for finding the (position of) last numeric
value in a range. The extension is due to Harlan Grove. How it works is
explained he

http://tinyurl.com/7ysq5

Adam wrote:
Hi Domenic,

I just saw this correspondence and I wonder if you could explain the formula
because i do not understand how it can return the right value (even though it
does!)
For instance, how do the formula know that the input 1/A1:A1000<"" refers
to the last cell?

Thanks
Adam

"Domenic" skrev:

Yes, definitely! Thanks for the reminder, Harlan!

Although, wouldn't 2 serve better as the lookup value?

For example, take the following table...

Bob a
Jack b
Jane c
Bob d
Jill e
Phil f
Bob g
Jason h

If you use...

=LOOKUP(1,1/(A1:A100="Bob"),B1:B100)

...the correct result is returned, that being "g".

However, if you use...

=LOOKUP(1,1/(A1:A8="Bob"),B1:B8)

...an incorrect result is returned, that being "d".

Using 2 as the lookup value returns the correct result regardless of
the range one uses.