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A customer walks into a 7-11 store and picks up four items.
-- How much do I pay? -- she asks.
The clerk punches a few numbers on a calculator as the customer watches on.
-- That will be exactly $7.11
The customer raises her brows.
-- Excuse me but didn't you just MULTIPLY the four prices, instead of adding them...?
-- Oh, yes, I'm sorry! Just a minute... -- says the clerk and this time adds the prices.
-- Here it is... $7.11
-- ???
-- Your four items add up to $7.11.
-- Well, here it is, but I guess I'll have to check myself ...
-- Sure, if anything is wrong please come back.
-- What are your opening hours?
-- 7-11. [A long time ago 7-11 stores were open from 7am to 11pm.]

QUESTION 1: What were the prices?

QUESTION 2: Could that mistake have occurred with fewer or more than 4 items?


Those who solved the puzzle first (Andreas Andersson and Luiz Borgonovo) received a free lunch, worth... $7.11