Biff

The first reading would be (1972-1367)/(10+14) = 25.21.

The second would be (2833 - 1972)/(13+10+12) = 24.6.

Thanks.

Terry

"T. Valko" wrote in message
...
Based on this data tell me what results you would expect:

.....Miles.....Gals.....Filled = Y.....MPG
.....1000.......12................................ ..
.....1367.......11.........Y......................
.....1623.......10................................ ..
.....1972.......14.........Y................??...
.....2200.......13................................ ..
.....2500.......10................................ ..
.....2833.......12.........Y................??...


--
Biff
Microsoft Excel MVP


"Terry Bennett" wrote in message
...
I have a worksheet used for calculating vehicle fuel economy statistics.
The columns a

A - Date
B - Mileometer reading
C - Amount of fuel added
D - Whether tank full or not ("Y" if full / blank if not)

In column E I want to display the Miles Per Gallon (MPG) based upon the
most recent fill-up. Hence, if the tank was filled, I need to devise a
formula that refers back to when it was last full (ie; when column C last
had a "Y" entered) and then subtracts today's mileage from that in column
B when the tank was last full. If the tank was not full then column E
remains blank until next time it is full.

I can only think of using VLOOKUP for this but not quite sure how as
there will be many instances of "Y" in column C - I just need the most
recent.

Any ideas?

Thanks.

Terry Bennett