Okay. First things first, let's find what the powers of 10 equal to. So 10^8 is 100,000,000. 1,000,000 * 2.25 is 225,000,000. The distance from Earth to Mars is 225,000,000 miles. 10^5 is 100,000. 100,000 * 1.5 is 150,000. One of NASA's space ships travels 150,000 miles per hour. Speed = distance/time. We divide the distance by time, 225,000,000/150,000 is 1,500. 1,500 in scientific notation is 1.5 * 10³. 10³ is 1,000 and 1,000 * 1.5 is 1,500. There. The ship will take 1,500 hours to reach Mars from Earth. The answer is B: 1.5 * 10³ hours.