[sk5t]

The above, only if you want to discard (filter) orders with an even number of things.

Also I'm not sure about the use of floating point here...

[kilotaras]

Ruby's select[1] is the same as java 8's filter[2].

[1] http://ruby-doc.org/core-2.2.3/Enumerable.html#method-i-sele... [2] https://docs.oracle.com/javase/8/docs/api/java/util/stream/S...