Question 889360
Sally can paint a room in 4 hours while it takes Steve 5 hours to paint the same room. How long would it take them to paint the room if they worked together ?
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In 1 hour, Sally can paint 1/4 of a room.
In 1 hour, Steve can paint 1/5 of a room.
Together, they can paint 1/4 + 1/5 of a room, = 9/20 of a room.
9/20 room/hour --> 20/9 hour per room.