Problem of the Week

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Spare Change

Posted: April 14, 2025

68 % of users got this correct

In a far off land called Algebria, named their currency is called Protons. This country only issues two types of coins to be used as Protons: one 8 Proton coin and one 11 Proton coin. This causes a slight dilemma since certain prices can not be paid exactly, such as 12 Protons. In Algebria, what is the highest price that cannot be paid with any combination of the two coins?

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