It takes Bill 4 hours to paint a wedding hall, and it takes Jessica 2 hours to paint the same hall. Working together, how many of these halls could they paint in 12 hours if they can continue painting at the same rate?

Answer 1

Bill can paint 1/4 of the hall in one hour because 1 / 4 = <<1/4=0.25>>0.25
Jessica can paint 1/2 of the hall in one hour because 1 / 2 = <<1/2=0.5>>0.5
Together, they can paint 0.75 of a hall in one hour because .25 + .5= <<.25+.5=0.75>>0.75
Together, they can paint 9 halls in 12 hours because 12 x 0.75 = <<12*0.75=9>>9. Answer: \boxed{9}.