A pipe can fill a cistern in 30 minutes and a waste-pipe can empty it in 1 hour. If both pipes are opened at once when the cistern is empty, how long will it take to fill the cistern?
plz plz solve it..I am confused

Sample response: if the graph passes the horizontaline test, then the function is one to one. functions that are one to one have inverses that a therefore, the inverse is a hinction compare your response to the sample response above. what did you include in your explanation? a reference to the horizontal-line test d a statement that the function is one-to-one the conclusion that the inverse is a function done