Provide your best answer for the following math problem. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The problem is: when working alone , painter w can paint a room in 2 hours , and working alone , painter x can paint the same room in r hours . when the two painters work together and independently , they can paint the room in 3 / 4 of an hour . what is the value of r ?
1 [ 1 / 5 ]
r = 3/2.