Each Saturday, a store reduces the price of any unsold
item by 10%. If an item was priced at $80, on Saturday
of the first week it is marked down to $72. At the end of
the second week, it drops to $64.80, and at the end of
the third week the price is decreased to $58.32. If this
continues for 10 weeks, what should be the selling
price for an item that was originally priced at $80?