You can paint a building in 9 hours. your friend can paint the same building in 12 hours. how long will it take the two of you working together to paint the building?

:i need some real : a store sells shirts to the public at one pricing scale and wholesale at another pricing scale. the tables below describe the cost, y, of x shirts. (after tables) how do the slopes of the lines created by each table compare? the slope of the public table is 3/4 of the slope of the wholesale table.the slope of the wholesale table is 3/4 of the slope of the public table.the slope of the public table is 12 times greater than the slope of the wholesale table.the slope of the wholesale table is 12 times greater than the slope of the public table.