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        riddles >> easy >> 10x10 Vending Machine
        
(Message started by: mattian on Jul 12^th, 2012, 12:47pm)

Title: 10x10 Vending Machine
Post by mattian on Jul 12^th, 2012, 12:47pm

Suppose you have a vending machine containing a single product. The vending machine has 10 columns with 10 units in each column for a total of 100 units.

The vending machine is full and you have sufficiently many coins to buy all the items in the machine.

There is a fixed probability (p) that the vend will fail - this probability is per vend.

If a vend fails, the remaining items in the selected column are blocked and the column becomes unusable.

To vend an item you are free to select any column that isn't blocked or empty.

Is there a particular strategy that can decrease the total loss (or blocked product) left in the machine? Or does it make no difference which column you choose?

For instance - is there a benefit to always choosing the shortest column? Or the longest column?

Title: Re: 10x10 Vending Machine
Post by towr on Jul 12^th, 2012, 1:06pm

[hide]It doesn't matter.
Order of picking columns doesn't matter, because if each vend is independent, then each column is independent. So it doesn't matter whether you first empty one column and then another or switch back and fro.[/hide]

Also, welcome back; been a few years, hasn't it.

Title: Re: 10x10 Vending Machine
Post by Grimbal on Jul 17^th, 2012, 8:54am

Yeah. It is like if you had 10 separate vending machines.