<PRE><B>Question 25940</B>
If doubling the work force to two tellers does not reduce the work time by half or more, then we must assume that the second teller is slower than the first teller.  The question is how much slower?


15 minutes/20 minutes = 0.75 = 75%
So, working together the two tellers were (100% - 75%) or 25% faster than the first teller working alone?


If we assume that the second teller is responsible for the 25% increase, then we can assume that working alone the second teller will take 25% more time than the first teller or 20 + 25%(20) = 25 minutes.


So, logic tells us that the second teller will take 25 minutes working alone.
I hope that is right.</PRE>