Q: The tremors of earthquake were felt at intervals of 15 seconds. The first tremor was felt at 8:54:57 and last tremor was felt at 10:45:12. How many times were the tremors felt? A: The answer is 441 Difference of times = 10:45:12 - 8:54:57 = 9:104:72 - 8:54:57 = 1:50 :15 = 3600 + 3000 + 15 = 6615 seconds. Now, 6615/15 = 441 Still confused? Kindly, drop your query in the comment section below.