Answer:
3.6 hours
Step-by-step explanation:
Blake can do work in hours = 9
Blake can do a part of work in 1 hour = 1/9
Ned can paint the same room in six hours.
Ned can do a part of work in 1 hour = 1/6
They can do a part of work together in 1 hour = 1/9 + 1/6
= 5/18
Now they can do 5/18 part of work in hour = 1
So, they can do whole work in hours = 1/(5/18)
= 3.6
Hence it will take 3.6 hours to paint the room if they work together.
