Newspaper Boy Problem. Decide how man papers to purchase, given that the demand is uncertain.

Example: The demand is $10,20,30,$ or $40$ newspaper on any given day. Purchase a newspaper for $20c$ and sell for $90c.$ The salvage value of an unsold newspaper is $5c,$ while the opportunity cost for newspapers has been estimated to be $15c$ for each newspaper that could have been sold but was not due to the lack of supply. Suppose that the purchasing strategies are $10,20,30,$ & $40.$

Payoff matrix