Hat puzzle 5 prisoners answer correctly and 5 do not. Note that the prisoners cannot find a strategy guaranteeing the release of more than 5 prisoners. Indeed, for a single prisoner, there are as many distributions of hat colors where he says the correct answer than there are where he does not. Hence, there are as many distributions of hat colors where 6 or more prisoners say the correct answer than there are where 4 or fewer do so. In this variant, a countably infinite number of prisoners, each with an unknown and randomly assigned red or blue hat line up single
Gallon as . The IEEE standard symbol for the gallon is gal. The gallon currently has one definition in the imperial system, and two definitions (liquid and dry) in the US customary system. Historically, there were many definitions and redefinitions. There were more than a few systems of liquid measurements in the pre-1884 United Kingdom. The imperial (UK) gallon, now defined as exactly litres (about 277.42 cubic inches), is used in some Commonwealth countries and was originally based on the volume of 10 pounds (approximately 4.54 kg) of water at . The imperial fluid ounce is defined as of an imperial