If letters of the word SACHIN are arranged in all possible ways and are written out as in a dictionary, then the word SACHIN appears at serial number

Letters appearing in the word SACHIN are A, C, H, I, N, SThe words beginning with letters A, C, H, I and N appear before the word SACHIN.There are 5(5!) = 600 words beginning with A, C, H, I and N.Word SACHIN appears is the first word beginning with S. Therefore, SACHIN appears at serial number 601.