Give the step-by-step reasoning process and then the final answer. The space station, Lupus-1, is an enormous spacecraft made up of three identical cylindrical structures that house the living quarters for the crew.  The three cylindrical structures are linked together by a series of tunnels that hold them together and allow the crew to move between cylinders. Each cylindrical structure contains 12 bedrooms, 7 bathrooms, and several kitchens. If the entire space station has 72 rooms, how many kitchens are there on the entire space station?
If there are 3 identical cylindrical structures, with a combined total of 72 rooms, then each individual cylindrical structure contains 72 / 3 = 24 rooms. In each 24 - room cylindrical structure, there are 24 - 12 - 7 = 5 kitchens. Thus, the entire, three - cylinder space station contains a total of 3 * 5 = 15 kitchens.
The final answer: 15.