Serous membrane is a thin membrane with two layers that lines and covers the wall and organs of the thoracic and abdominopelvic cavities, these organs includes the heart, lungs and the body cavity. Its role is to prevent friction between the organ and the body cavity wall. The membrane is formed by simple squamous epithelium which are filled with connective tissues.
Well it is triples you can tell that it is a division question. So triples means by 3. The equation is 2,551,500 = d X 3^6. So, now 2,511,500 / 729 is your final answer, 3,500. Hope it helps :)
