Town A is located at 30 degrees West longitude. When it is 9:00 am in Town A, it is 6:00 pm in Town B. What is the longitude of Town B?

Time in Town A = 9:00 am
Time in Town B = 6:00 pm
To find the difference, convert 6:00 pm to 24-hour format, which is 18:00.
Time difference = $18:00 - 9:00 = 9$ hours.

Since the time in Town B (6:00 pm) is later than the time in Town A (9:00 am), Town B is located to the East of Town A.

The Earth rotates $360^\circ$ in 24 hours.
This means 1 hour corresponds to $\frac{360^\circ}{24} = 15^\circ$ of longitude.
Longitude difference = $9 \text{ hours} \times 15^\circ/\text{hour} = 135^\circ$.

Town A is at $30^\circ$ W.
Town B is $135^\circ$ East of Town A.
Starting from $30^\circ$ W, moving $30^\circ$ East brings us to the Prime Meridian ($0^\circ$).
Remaining longitude to move East = $135^\circ - 30^\circ = 105^\circ$.
Since we have moved past the Prime Meridian, Town B is $105^\circ$ East of the Prime Meridian.

Alternatively, using signed longitudes (West is negative, East is positive):
Longitude of A = $-30^\circ$
Longitude of B = Longitude of A + Longitude difference
Longitude of B = $-30^\circ + 135^\circ = 105^\circ$.
Since the result is positive, it is $105^\circ$ E.

The longitude of Town B is $\text{105}^\circ \text{ E}$.