Provide your best answer for the following question. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The question is: Joe and John and sylvia were all running errands. They split up their tasks into blocks that were near each other and then each person took one block of tasks.  They did this because it gave them more what?
efficiency
flexibility.