I am writing a spreadsheet that will create a cut list and cost list based on
a group of measurements. I need to be able to figure out how to make the
list of measurements fit best into materials that are 20' long.

For instance:
11'3"
5'8"
17'3 3/4"
1'5 1/2"
and so on up to 30 or 40 measurements.

I need to know what combination of pieces will fit into 20' pieces of pipe
with the least amount of waste and how many 20' pieces of pipe will be needed
to complete.