Answer:
The flight to Portland takes 10.6 hours.
Explanation:
To find the time of flight to Portland we need to calculate the distance traveled by using the equation:

Where:
v: is the speed = 204 mph (return flight)
t: is the time = 12 h (return flight)

Now, we can find the time of flight to Portland using v = 232 mph:

Therefore, the flight to Portland takes 10.6 hours.
I hope it helps you!