Three workers have to do a certain job. the first worker can finish the job in 8 hours. the second worker can finish the job in 4 hours. the third worker can also finish the job in 4 hours. how long will it take the three workers to finish the job if they work together?
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Two sides of a triangle mesure 20cm and 30cm. what is the measure of the third side

Asays "we are both knaves" and b says nothing. exercises 24–31 relate to inhabitants of an island on which there are three kinds of people: knights who always tell the truth, knaves who always lie, and spies (called normals by smullyan [sm78]) who can either lie or tell the truth. you encounter three people, a, b, and c. you know one of these people is a knight, one is a knave, and one is a spy. each of the three people knows the type of person each of other two is. for each of these situations, if possible, determine whether there is a unique solution and determine who the knave, knight, and spy are. when there is no unique solution, list all possible solutions or state that there are no solutions. 24. a says "c is the knave," b says, "a is the knight," and c says "i am the spy."

The variable in a relation who’s value depends on the value of the independent variable is called what?