Respuesta :
16, because if they both do half, 12/2=6 and 20/2=10 10+6=16. I hope that this is correct.
(Corrected the Answer :p )
Hannah can paint the room in 20 hours. So each hour, Hannah paints 1/20 of the room.
Destiny can paint the room in 12 hours. So each hour, Destiny paints 1/16 of the room.
In 1 hour, both of them can paint 1/20 + 1/16 = 4/80 + 5/80 = 9/80.
As you noticed before, proportion painted in 1 hour and the total time to paint the whole room were inversed. Same thing for both of them.
They both paint 9/80 of the room in 1 hour. So to paint the whole room, they take 80/9= 8.9 hours (80/9 inverse of 9/80).
Hope this Helps! :)
Hannah can paint the room in 20 hours. So each hour, Hannah paints 1/20 of the room.
Destiny can paint the room in 12 hours. So each hour, Destiny paints 1/16 of the room.
In 1 hour, both of them can paint 1/20 + 1/16 = 4/80 + 5/80 = 9/80.
As you noticed before, proportion painted in 1 hour and the total time to paint the whole room were inversed. Same thing for both of them.
They both paint 9/80 of the room in 1 hour. So to paint the whole room, they take 80/9= 8.9 hours (80/9 inverse of 9/80).
Hope this Helps! :)
