Hello!
I believe the answer is they can, together, paint the room in 8.9hrs.
Hope this helps! ☺♥
Answer: Union of two sets.
Explanation: "An element is in the union of two sets if it is in the first set, the second set, or both. The symbol we use for the union is ∪ . The word that you will often see that indicates a union is "or".
Your Welcome :-)