Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
NCTM or The Math Forum.


Math Forum
»
Discussions
»
sci.math.*
»
sci.math
Notice: We are no longer accepting new posts, but the forums will continue to be readable.
Topic:
Recursion Problem
Replies:
11
Last Post:
Nov 22, 2011 9:44 PM




Re: Recursion Problem
Posted:
Nov 17, 2011 9:52 AM


On Nov 17, 4:13 am, William Elliot <ma...@rdrop.com> wrote:
> > Suppose we have a container of M&Ms. > > Each year, I add some amount of M&Ms to my container. > > Including possibly zero M&M's?
No: the input each year is always positive... > > > For year i, let's call the input A_i. The input will be known for each > > year (think of it as a given data value). > > Each year, I take the *same* amount of M&M's out, which I'll denote as > > B (think of this as a parameter). > > So the net amount of M&Ms in yr i that I add to my container = F_i = > > A_i  B > > That's a rather risque expression: So the net amount of M&Ms in your eye > that I add to my container = F_i = A_i  B.
I think I missed a joke, but that's OK. Anyhow, yes the net amt of M&Ms = A_iB (realizing that when we say "add to the container", that A_iB could be negative)>
> > > The question is this: > > "If I know the influxes for each year and start out with no deficit > > what is the maximum fixed amount of M&Ms (i.e. the maximum value for > > B) I can take out so at the end of n years, I will have no deficit?" > > min{ a1, a2,.. a_n } > I assume the A's are capital. I know this is not the answer though, as I can construct a counterexample (in fact "to" problem given is one such CE)
> > Not an easy problem, and I don't think it probably has a "nice" > > solution, but just thought I would see if anyone had a better thought. > > It's made messy by the results depending not only > on the values of the a's but also on their order.
YES! You can take that same toy problem, rearrange them and get a different answer. One thing I believe is true is that Average(A_i) is an upper bound on the value of the soln for B.



